diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index b276add3..452f5f94 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -17,16 +17,11 @@ jobs:
         os:
           - ubuntu-latest
         ocaml-compiler:
-          - "4.13"
-          - "4.14"
-          - "5.0"
-          - "5.1"
-          - "5.2"
+          - "5.3"
+          - "5.4"
         include:
           - os: macos-latest
-            ocaml-compiler: "4.14"
-          - os: macos-latest
-            ocaml-compiler: "5.2"
+            ocaml-compiler: "5.4"
 
     runs-on: ${{ matrix.os }}
 
@@ -44,8 +39,15 @@ jobs:
         if: runner.os == 'macOS'
         run: brew update && brew reinstall openssl@3
 
+      - name: Install external dependencies
+        # The version of binaryen available in ubuntu is too old and doesn't
+        # contain wasm-merge needed by wasm_of_ocaml.
+        if: runner.os == 'Linux'
+        run: |
+          curl -sL https://github.com/WebAssembly/binaryen/releases/download/version_129/binaryen-version_129-x86_64-linux.tar.gz | sudo tar xz -C /usr/local --strip-components=1
+
       - run: opam pin add -n eliom https://github.com/ocsigen/eliom.git
 
       - run: opam install . --deps-only
 
-      - run: opam exec -- make
+      - run: opam exec -- dune build @install
diff --git a/.gitignore b/.gitignore
index dcfbd6c2..e35d8850 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,8 +1 @@
-.depend
-_client
-_deps
-_server
-lib
-_opam
-doc/client
-doc/server
+_build
diff --git a/META.in b/META.in
deleted file mode 100644
index 73f3b274..00000000
--- a/META.in
+++ /dev/null
@@ -1,19 +0,0 @@
-names = "@@PKG_NAME@@"
-version = "@@PKG_VERS@@"
-description = "@@PKG_DESC@@"
-
-package "server" (
-  requires = "@@SERVER_REQUIRES@@"
-  directory = "server"
-  archive(byte) = "@@SERVER_ARCHIVES_BYTE@@"
-  archive(byte, plugin) = "@@SERVER_ARCHIVES_BYTE@@"
-  archive(native) = "@@SERVER_ARCHIVES_NATIVE@@"
-  archive(native, plugin) = "@@SERVER_ARCHIVES_NATIVE_PLUGIN@@"
-)
-
-package "client" (
- requires = "@@CLIENT_REQUIRES@@"
- directory = "client"
- archive(byte) = "@@CLIENT_ARCHIVES_BYTE@@"
- archive(byte, plugin) = "@@CLIENT_ARCHIVES_BYTE@@"
-)
diff --git a/Makefile b/Makefile
deleted file mode 100644
index 71e97434..00000000
--- a/Makefile
+++ /dev/null
@@ -1,228 +0,0 @@
-
-##----------------------------------------------------------------------
-## DISCLAIMER
-##
-## This file contains the rules to make an ocsigen package. The project
-## is configured through the variables in the file Makefile.options.
-##----------------------------------------------------------------------
-
-include Makefile.options
-
-##----------------------------------------------------------------------
-##			      Internals
-
-## Required binaries
-ELIOMC            := eliomc -ppx ${WARNING_FLAGS}
-ELIOMOPT          := eliomopt -ppx ${WARNING_FLAGS}
-JS_OF_ELIOM       := js_of_eliom -ppx
-ELIOMDEP          := eliomdep
-OCAMLFIND         := ocamlfind
-
-## Where to put intermediate object files.
-## - ELIOM_{SERVER,CLIENT}_DIR must be distinct
-## - ELIOM_CLIENT_DIR must not be the local dir.
-## - ELIOM_SERVER_DIR could be ".", but you need to
-##   remove it from the "clean" rules...
-export ELIOM_SERVER_DIR := _server
-export ELIOM_CLIENT_DIR := _client
-export ELIOM_TYPE_DIR   := _server
-
-ifeq ($(DEBUG),yes)
-  GENERATE_DEBUG ?= -g
-endif
-
-ifeq ($(NATIVE),yes)
-  OPT_RULE = opt
-endif
-
-##----------------------------------------------------------------------
-## General
-
-.PHONY: all byte opt doc
-all: byte $(OPT_RULE)
-byte:: $(LIBDIR)/${PKG_NAME}.server.cma $(LIBDIR)/${PKG_NAME}.client.cma
-opt:: $(LIBDIR)/${PKG_NAME}.server.cmxs
-
-##----------------------------------------------------------------------
-## Aux
-
-eliomdep=$(shell $(ELIOMDEP) $(1) -ppx -sort $(2) $(filter %.eliom %.ml,$(3))))
-objs=$(patsubst %.ml,$(1)/%.$(2),$(patsubst %.eliom,$(1)/%.$(2),$(filter %.eliom %.ml,$(3))))
-depsort=$(call objs,$(1),$(2),$(call eliomdep,$(3),$(4),$(5)))
-
-$(LIBDIR):
-	mkdir $(LIBDIR)
-
-##----------------------------------------------------------------------
-## Server side compilation
-
-## make it more elegant ?
-SERVER_DIRS     := $(shell echo $(foreach f, $(SERVER_FILES), $(dir $(f))) |  tr ' ' '\n' | sort -u | tr '\n' ' ')
-SERVER_DEP_DIRS := ${addprefix -eliom-inc ,${SERVER_DIRS}}
-SERVER_INC_DIRS := ${addprefix -I $(ELIOM_SERVER_DIR)/, ${SERVER_DIRS}}
-
-SERVER_INC  := ${addprefix -package ,${SERVER_PACKAGES} ${SERVER_PPX_PACKAGES}}
-
-${ELIOM_TYPE_DIR}/%.type_mli: %.eliom
-	${ELIOMC} -infer ${SERVER_INC} ${SERVER_INC_DIRS} $<
-
-$(LIBDIR)/$(PKG_NAME).server.cma: $(call objs,$(ELIOM_SERVER_DIR),cmo,$(SERVER_FILES)) | $(LIBDIR)
-	${ELIOMC} -a -o $@ $(GENERATE_DEBUG) \
-          $(call depsort,$(ELIOM_SERVER_DIR),cmo,-server,$(SERVER_INC),$(SERVER_FILES))
-
-$(LIBDIR)/$(PKG_NAME).server.cmxa: $(call objs,$(ELIOM_SERVER_DIR),cmx,$(SERVER_FILES)) | $(LIBDIR)
-	${ELIOMOPT} -a -o $@ $(GENERATE_DEBUG) \
-          $(call depsort,$(ELIOM_SERVER_DIR),cmx,-server,$(SERVER_INC),$(SERVER_FILES))
-
-%.cmxs: %.cmxa
-	$(ELIOMOPT) -shared -linkall -o $@ $(GENERATE_DEBUG) $<
-
-${ELIOM_SERVER_DIR}/%.cmi: %.mli
-	${ELIOMC} -c ${SERVER_INC} ${SERVER_INC_DIRS} $(GENERATE_DEBUG) $<
-
-${ELIOM_SERVER_DIR}/%.cmi: %.eliomi
-	${ELIOMC} -c ${SERVER_INC} ${SERVER_INC_DIRS} $(GENERATE_DEBUG) $<
-
-${ELIOM_SERVER_DIR}/%.cmo: %.ml
-	${ELIOMC} -c ${SERVER_INC} ${SERVER_INC_DIRS} $(GENERATE_DEBUG) $<
-${ELIOM_SERVER_DIR}/%.cmo: %.eliom
-	${ELIOMC} -c ${SERVER_INC} ${SERVER_INC_DIRS} $(GENERATE_DEBUG) $<
-
-${ELIOM_SERVER_DIR}/%.cmx: %.ml
-	${ELIOMOPT} -c ${SERVER_INC} ${SERVER_INC_DIRS} $(GENERATE_DEBUG) $<
-${ELIOM_SERVER_DIR}/%.cmx: %.eliom
-	${ELIOMOPT} -c ${SERVER_INC} ${SERVER_INC_DIRS} $(GENERATE_DEBUG) $<
-
-
-##----------------------------------------------------------------------
-## Client side compilation
-
-## make it more elegant ?
-CLIENT_DIRS     := $(shell echo $(foreach f, $(CLIENT_FILES), $(dir $(f))) |  tr ' ' '\n' | sort -u | tr '\n' ' ')
-CLIENT_DEP_DIRS := ${addprefix -eliom-inc ,${CLIENT_DIRS}}
-CLIENT_INC_DIRS := ${addprefix -I $(ELIOM_CLIENT_DIR)/,${CLIENT_DIRS}}
-
-CLIENT_LIBS := ${addprefix -package ,${CLIENT_PACKAGES} ${CLIENT_PPX_PACKAGES}}
-CLIENT_INC  := ${addprefix -package ,${CLIENT_PACKAGES} ${CLIENT_PPX_PACKAGES}}
-
-CLIENT_OBJS := $(filter %.eliom %.ml, $(CLIENT_FILES))
-CLIENT_OBJS := $(patsubst %.eliom,${ELIOM_CLIENT_DIR}/%.cmo, ${CLIENT_OBJS})
-CLIENT_OBJS := $(patsubst %.ml,${ELIOM_CLIENT_DIR}/%.cmo, ${CLIENT_OBJS})
-
-$(LIBDIR)/$(PKG_NAME).client.cma: $(call objs,$(ELIOM_CLIENT_DIR),cmo,$(CLIENT_FILES)) | $(LIBDIR)
-	${JS_OF_ELIOM} -a -o $@ $(GENERATE_DEBUG) \
-          $(call depsort,$(ELIOM_CLIENT_DIR),cmo,-client,$(CLIENT_INC),$(CLIENT_FILES))
-
-${ELIOM_CLIENT_DIR}/%.cmi: %.mli
-	${JS_OF_ELIOM} -c ${CLIENT_INC} ${CLIENT_INC_DIRS} $(GENERATE_DEBUG) $<
-
-${ELIOM_CLIENT_DIR}/%.cmo: %.eliom
-	${JS_OF_ELIOM} -c ${CLIENT_INC} ${CLIENT_INC_DIRS} $(GENERATE_DEBUG) $<
-${ELIOM_CLIENT_DIR}/%.cmo: %.ml
-	${JS_OF_ELIOM} -c ${CLIENT_INC} ${CLIENT_INC_DIRS} $(GENERATE_DEBUG) $<
-
-${ELIOM_CLIENT_DIR}/%.cmi: %.eliomi
-	${JS_OF_ELIOM} -c ${CLIENT_INC} ${CLIENT_INC_DIRS} $(GENERATE_DEBUG) $<
-
-##----------------------------------------------------------------------
-## Installation
-
-CLIENT_CMO=$(wildcard $(addsuffix /$(MODULE_PREFIX)*.cmo,$(addprefix $(ELIOM_CLIENT_DIR)/,$(CLIENT_DIRS))))
-CLIENT_CMI=$(wildcard $(addsuffix /$(MODULE_PREFIX)*.cmi,$(addprefix $(ELIOM_CLIENT_DIR)/,$(CLIENT_DIRS))))
-SERVER_CMI=$(wildcard $(addsuffix /$(MODULE_PREFIX)*.cmi,$(addprefix $(ELIOM_SERVER_DIR)/,$(SERVER_DIRS))))
-SERVER_CMX=$(wildcard $(addsuffix /$(MODULE_PREFIX)*.cmx,$(addprefix $(ELIOM_SERVER_DIR)/,$(SERVER_DIRS))))
-
-basename_for_each = $(shell echo $(foreach f,$(1),$(shell basename $(f))))
-CLIENT_CMO_META=$(call basename_for_each, $(call depsort,$(ELIOM_CLIENT_DIR),cmo,-client,$(CLIENT_INC),$(CLIENT_FILES)))
-
-META: META.in
-	sed -e 's#@@PKG_NAME@@#$(PKG_NAME)#g' \
-		-e 's#@@PKG_VERS@@#$(PKG_VERS)#g' \
-		-e 's#@@PKG_DESC@@#$(PKG_DESC)#g' \
-		-e 's#@@CLIENT_REQUIRES@@#$(CLIENT_PACKAGES)#g' \
-		-e 's#@@CLIENT_ARCHIVES_BYTE@@#$(CLIENT_CMO_META)#g' \
-		-e 's#@@SERVER_REQUIRES@@#$(SERVER_PACKAGES)#g' \
-		-e 's#@@SERVER_ARCHIVES_BYTE@@#$(PKG_NAME).server.cma#g' \
-		-e 's#@@SERVER_ARCHIVES_NATIVE@@#$(PKG_NAME).server.cmxa#g' \
-		-e 's#@@SERVER_ARCHIVES_NATIVE_PLUGIN@@#$(PKG_NAME).server.cmxs#g' \
-		$< > $@
-
-install: all META
-	$(OCAMLFIND) install $(PKG_NAME) META
-	mkdir -p `$(OCAMLFIND) query $(PKG_NAME)`/client
-	mkdir -p `$(OCAMLFIND) query $(PKG_NAME)`/server
-	cp $(CLIENT_CMI) `$(OCAMLFIND) query $(PKG_NAME)`/client
-	cp $(CLIENT_CMO) `$(OCAMLFIND) query $(PKG_NAME)`/client
-	cp $(SERVER_CMI) `$(OCAMLFIND) query $(PKG_NAME)`/server
-	cp $(SERVER_CMX) `$(OCAMLFIND) query $(PKG_NAME)`/server
-	cp $(LIBDIR)/$(PKG_NAME).server.cm* `$(OCAMLFIND) query $(PKG_NAME)`/server
-	cp $(LIBDIR)/$(PKG_NAME).server.a `$(OCAMLFIND) query $(PKG_NAME)`/server
-
-uninstall:
-	rm -rf `$(OCAMLFIND) query $(PKG_NAME)`/client
-	rm -rf `$(OCAMLFIND) query $(PKG_NAME)`/server
-	$(OCAMLFIND) remove $(PKG_NAME)
-
-reinstall: uninstall install
-
-##----------------------------------------------------------------------
-## Dependencies
-
-ifneq ($(MAKECMDGOALS),distclean)
-ifneq ($(MAKECMDGOALS),clean)
-ifneq ($(MAKECMDGOALS),depend)
-    include .depend
-endif
-endif
-endif
-
-DEPSDIR := _deps
-
-.depend: $(patsubst %,$(DEPSDIR)/%.server,$(SERVER_FILES)) $(patsubst %,$(DEPSDIR)/%.client,$(CLIENT_FILES))
-	cat $^ > $@
-
-$(DEPSDIR)/%.server: % | $(DEPSDIR)
-	$(ELIOMDEP) -server -ppx $(SERVER_INC) $(SERVER_DEP_DIRS) $< > $@
-
-$(DEPSDIR)/%.client: % | $(DEPSDIR)
-	$(ELIOMDEP) -client -ppx $(CLIENT_INC) $(CLIENT_DEP_DIRS) $< > $@
-
-$(DEPSDIR):
-	mkdir -p $@
-	mkdir -p $(addprefix $@/, ${CLIENT_DIRS})
-	mkdir -p $(addprefix $@/, ${SERVER_DIRS})
-
-##----------------------------------------------------------------------
-## Documentation
-
-COMMON_OPTIONS := -colorize-code -stars -sort
-
-eliomdoc_wiki = ODOC_WIKI_SUBPROJECT="$(1)" eliomdoc -$(1) -ppx -intro doc/indexdoc.$(1) $(COMMON_OPTIONS) -i $(shell ocamlfind query wikidoc) -g odoc_wiki.cma -d doc/$(1)/wiki $(2)
-eliomdoc_html = ODOC_WIKI_SUBPROJECT="$(1)" eliomdoc -$(1) -ppx -intro doc/indexdoc.$(1) $(COMMON_OPTIONS) -html -d doc/$(1)/html $(2)
-
-doc: doc-clean
-	mkdir -p doc/client/html
-	mkdir -p doc/client/wiki
-	mkdir -p doc/server/html
-	mkdir -p doc/server/wiki
-	$(call eliomdoc_html,client, $(CLIENT_INC) $(CLIENT_INC_DIRS) $(CLIENT_FILES_DOC))
-	$(call eliomdoc_wiki,client, $(CLIENT_INC) $(CLIENT_INC_DIRS) $(CLIENT_FILES_DOC))
-	$(call eliomdoc_html,server, $(SERVER_INC) $(SERVER_INC_DIRS) $(SERVER_FILES_DOC))
-	$(call eliomdoc_wiki,server, $(SERVER_INC) $(SERVER_INC_DIRS) $(SERVER_FILES_DOC))
-
-doc-clean:
-	rm -rf doc/client
-	rm -rf doc/server
-
-##----------------------------------------------------------------------
-## Clean up
-
-clean:
-	-rm -f .depend
-	-rm -f *.cm[ioax] *.cmxa *.cmxs *.o *.a *.annot
-	-rm -f *.type_mli
-	-rm -f META
-	-rm -rf ${ELIOM_CLIENT_DIR} ${ELIOM_SERVER_DIR} ${LIBDIR} ${DEPSDIR}
-
-distclean: clean
-	-rm -rf $(DEPSDIR) .depend
diff --git a/Makefile.options b/Makefile.options
deleted file mode 100644
index f598b5c5..00000000
--- a/Makefile.options
+++ /dev/null
@@ -1,62 +0,0 @@
-#----------------------------------------------------------------------
-#           SETTINGS FOR YOUR PACKAGE
-#----------------------------------------------------------------------
-
-# Package name for your
-PKG_NAME := ocsigen-toolkit
-PKG_VERS := 1.1
-PKG_DESC := reusable UI components meant for Eliom applications
-
-# Source files for the server
-SERVER_FILES := $(wildcard \
-  src/*.ml* \
-  src/*.eliom* \
-  src/widgets/*.eliom* \
-)
-
-# Source files for the client
-CLIENT_FILES := $(wildcard \
-  src/*.eliom* \
-  src/widgets/*.eliom* \
-)
-
-# Source files for the server
-SERVER_FILES_DOC := $(wildcard \
-  src/*.eliomi \
-  src/*.mli \
-  src/widgets/*.eliomi \
-)
-
-# Source files for the client
-CLIENT_FILES_DOC := $(wildcard \
-  src/*.eliomi \
-  src/widgets/*.eliomi \
-)
-
-# Template directory (used when installing template with distillery)
-TEMPLATE_DIR := template.distillery
-
-# Template name (name used by distillery)
-TEMPLATE_NAME := none.pgocaml
-
-# OCamlfind packages for the server
-SERVER_PACKAGES := calendar
-SERVER_PPX_PACKAGES := js_of_ocaml-ppx_deriving_json
-# OCamlfind packages for the client
-CLIENT_PACKAGES := calendar js_of_ocaml js_of_ocaml-lwt
-CLIENT_PPX_PACKAGES := js_of_ocaml-ppx js_of_ocaml-ppx_deriving_json
-
-# Debug package (yes/no): Debugging info in compilation
-DEBUG := yes
-
-# Native mode (yes/no): Compile also with native mode (it will always
-# compile with byte mode)
-NATIVE := yes
-
-# Package's library $(PKG_NAME).{client,server}.cma (a,cmxa,cmxs only
-# server side)
-LIBDIR := lib/
-
-WARNING_FLAGS=-w +A@3-4@5..16@20..43-44@45..68-69-70
-
-MODULE_PREFIX = ot
diff --git a/dune b/dune
new file mode 100644
index 00000000..4293baf3
--- /dev/null
+++ b/dune
@@ -0,0 +1,7 @@
+(vendored_dirs ocsigen-dune-rules)
+
+; Install the CSS files into share/ocsigen-toolkit/css/
+(install
+ (section share)
+ (files
+  (glob_files css/*.css)))
diff --git a/dune-project b/dune-project
new file mode 100644
index 00000000..11e6f5ad
--- /dev/null
+++ b/dune-project
@@ -0,0 +1,44 @@
+(lang dune 3.18)
+
+(name ocsigen-toolkit)
+
+(generate_opam_files true)
+
+(source
+ (github ocsigen/ocsigen-toolkit))
+
+(homepage "http://www.ocsigen.org")
+
+(authors "dev@ocsigen.org")
+
+(maintainers "dev@ocsigen.org")
+
+(license "LGPL-2.1-only WITH OCaml-LGPL-linking-exception")
+
+(maintenance_intent "(latest)")
+
+(dialect
+ (name "eliom-server")
+ (implementation
+  (extension "eliom"))
+ (interface
+  (extension "eliomi")))
+
+(package
+ (name ocsigen-toolkit)
+ (synopsis
+  "Reusable UI components for Eliom applications (client only, or client-server)")
+ (description
+  "The Ocsigen Toolkit is a set of user interface widgets that facilitate the development of Eliom applications.")
+ (depends
+  (ocaml
+   (>= "4.08.0"))
+  (js_of_ocaml
+   (>= "6.0.0"))
+  (eliom
+   (>= "11.0.0"))
+  (calendar
+   (>= "2.0.0"))
+  ; ocsigen-dune-rules dependencies
+  cmdliner
+  ocsigen-ppx-rpc))
diff --git a/ocsigen-dune-rules/.gitignore b/ocsigen-dune-rules/.gitignore
new file mode 100644
index 00000000..e35d8850
--- /dev/null
+++ b/ocsigen-dune-rules/.gitignore
@@ -0,0 +1 @@
+_build
diff --git a/ocsigen-dune-rules/.ocamlformat b/ocsigen-dune-rules/.ocamlformat
new file mode 100644
index 00000000..dbc03d39
--- /dev/null
+++ b/ocsigen-dune-rules/.ocamlformat
@@ -0,0 +1 @@
+version = 0.28.1
diff --git a/ocsigen-dune-rules/LICENSE b/ocsigen-dune-rules/LICENSE
new file mode 100644
index 00000000..877734eb
--- /dev/null
+++ b/ocsigen-dune-rules/LICENSE
@@ -0,0 +1,21 @@
+# MIT License
+
+Copyright (c) 2026 Tarides, Jules Aguillon
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/ocsigen-dune-rules/README.md b/ocsigen-dune-rules/README.md
new file mode 100644
index 00000000..f204f9c1
--- /dev/null
+++ b/ocsigen-dune-rules/README.md
@@ -0,0 +1,58 @@
+# ocsigen-dune-rules
+
+Generate Dune rules for building a client/server application or library.
+
+## Usage
+
+The following `dune` file builds the client and server parts of your library.
+Place it in a directory containing `*.eliom` files.
+
+`lib/dune`:
+```dune
+(library
+ (public_name my_lib.server)
+ (name my_lib)
+ (modes byte native)
+ (wrapped false)
+ (preprocess
+  (pps
+   eliom.ppx.server
+   ocsigen-ppx-rpc
+   --rpc-raw))
+ (libraries eliom.server js_of_ocaml))
+
+(subdir
+ client
+ (library
+  (public_name my_lib.client)
+  (name my_lib)
+  (modes byte)
+  (wrapped false)
+  (preprocess
+   (pps eliom.ppx.client js_of_ocaml-ppx))
+  (libraries eliom.client js_of_ocaml js_of_ocaml-lwt))
+ (dynamic_include ../dune.client))
+
+(rule
+ (deps
+  (glob_files *.eliom)
+  (glob_files *.eliomi))
+ (action
+  (with-stdout-to
+   dune.client
+   (run ocsigen-dune-rules .))))
+```
+
+You must also tell Dune that `*.eliom` files contain source code by adding this to your `dune-project` file:
+
+`dune-project`:
+```dune
+(dialect
+ (name "eliom-server")
+ (implementation
+  (extension "eliom"))
+ (interface
+  (extension "eliomi")))
+```
+
+See [ocsigen-toolkit](https://github.com/ocsigen/ocsigen-toolkit/tree/master) for a working example.
diff --git a/ocsigen-dune-rules/dune-project b/ocsigen-dune-rules/dune-project
new file mode 100644
index 00000000..313fc1ce
--- /dev/null
+++ b/ocsigen-dune-rules/dune-project
@@ -0,0 +1,19 @@
+(lang dune 3.14)
+
+(name ocsigen-dune-rules)
+
+(cram enable)
+
+(generate_opam_files true)
+
+(authors "Jules Aguillon <jules@j3s.fr>")
+
+(maintainers "Jules Aguillon <jules@j3s.fr>")
+
+(license MIT)
+
+(package
+ (name ocsigen-dune-rules)
+ (synopsis
+  "Generate Dune rules for building a client/server application or library.")
+ (depends ocaml cmdliner ocsigen-ppx-rpc eliom))
diff --git a/ocsigen-dune-rules/ocsigen-dune-rules.opam b/ocsigen-dune-rules/ocsigen-dune-rules.opam
new file mode 100644
index 00000000..8914b4cd
--- /dev/null
+++ b/ocsigen-dune-rules/ocsigen-dune-rules.opam
@@ -0,0 +1,29 @@
+# This file is generated by dune, edit dune-project instead
+opam-version: "2.0"
+synopsis:
+  "Generate Dune rules for building a client/server application or library."
+maintainer: ["Jules Aguillon <jules@j3s.fr>"]
+authors: ["Jules Aguillon <jules@j3s.fr>"]
+license: "MIT"
+depends: [
+  "dune" {>= "3.14"}
+  "ocaml"
+  "cmdliner"
+  "ocsigen-ppx-rpc"
+  "eliom"
+  "odoc" {with-doc}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+]
diff --git a/ocsigen-dune-rules/ocsigen-dune-rules/dune b/ocsigen-dune-rules/ocsigen-dune-rules/dune
new file mode 100644
index 00000000..778b68e6
--- /dev/null
+++ b/ocsigen-dune-rules/ocsigen-dune-rules/dune
@@ -0,0 +1,4 @@
+(executable
+ (public_name ocsigen-dune-rules)
+ (name main)
+ (libraries cmdliner))
diff --git a/ocsigen-dune-rules/ocsigen-dune-rules/gen_rules.ml b/ocsigen-dune-rules/ocsigen-dune-rules/gen_rules.ml
new file mode 100644
index 00000000..ff004966
--- /dev/null
+++ b/ocsigen-dune-rules/ocsigen-dune-rules/gen_rules.ml
@@ -0,0 +1,38 @@
+let pf = Printf.printf
+let spf = Printf.sprintf
+
+let gen_eliom_ppx_rule ~target ~input ~args =
+  (* The [chdir] instruction is needed to obtain the correct path for
+     [-loc-filename] to be used in error messages. *)
+  pf
+    {|(rule
+ (with-stdout-to %s
+  (chdir %%{workspace_root}
+   (run ocsigen-ppx-client -as-pp -loc-filename %%{dep:%s} %s %%{dep:%s}))))
+|}
+    target input (String.concat " " args) input
+
+let gen_rule_for_module ~server_rel_prefix ~impl fname =
+  let target = Filename.basename fname in
+  let fname_no_ext = Filename.remove_extension fname in
+  let input = Filename.concat server_rel_prefix fname in
+  if Filename.extension fname_no_ext = ".pp" then ()
+  else
+    let args =
+      if impl then
+        let server_cmo = Filename.concat server_rel_prefix fname_no_ext in
+        [ "--impl"; "-server-cmo"; spf "%%{cmo:%s}" server_cmo ]
+      else [ "--intf" ]
+    in
+    gen_eliom_ppx_rule ~target ~input ~args
+
+(** Relative path to server modules from the generated client modules. *)
+let server_rel_prefix = ".."
+
+let gen_rule_for_file fname =
+  match Filename.extension fname with
+  | ".eliom" -> gen_rule_for_module ~server_rel_prefix ~impl:true fname
+  | ".eliomi" -> gen_rule_for_module ~server_rel_prefix ~impl:false fname
+  | _ -> ()
+
+let run files = List.iter gen_rule_for_file files
diff --git a/ocsigen-dune-rules/ocsigen-dune-rules/main.ml b/ocsigen-dune-rules/ocsigen-dune-rules/main.ml
new file mode 100644
index 00000000..7b608f24
--- /dev/null
+++ b/ocsigen-dune-rules/ocsigen-dune-rules/main.ml
@@ -0,0 +1,20 @@
+let run dir =
+  let files = Utils.list_dir dir in
+  let files = List.filter (Fun.negate Utils.is_dir) files in
+  Gen_rules.run files
+
+open Cmdliner
+
+let arg_dir =
+  let doc = "Directory containing the Eliom modules." in
+  Arg.(required & pos 0 (some dir) None & info ~doc ~docv:"DIR" [])
+
+let cmd =
+  let term = Term.(const run $ arg_dir) in
+  let doc =
+    "Generate dune rules for building an ocsigen application or library."
+  in
+  let info = Cmd.info "ocsigen-dune-rules" ~version:"%%VERSION%%" ~doc in
+  Cmd.v info term
+
+let () = exit (Cmd.eval cmd)
diff --git a/ocsigen-dune-rules/ocsigen-dune-rules/utils.ml b/ocsigen-dune-rules/ocsigen-dune-rules/utils.ml
new file mode 100644
index 00000000..0b9e1825
--- /dev/null
+++ b/ocsigen-dune-rules/ocsigen-dune-rules/utils.ml
@@ -0,0 +1,13 @@
+(** List the content of a directory. Returns qualified paths. Returned path
+    doesn't contain [./] if [p] is equal to ["."]. *)
+let list_dir p =
+  (* Let [Sys_error] escape. *)
+  let files = Sys.readdir p in
+  (* Sorted for reproducibility. *)
+  Array.sort String.compare files;
+  let concat_p = if p = "." then Fun.id else Filename.concat p in
+  Array.iteri (fun i fname -> files.(i) <- concat_p fname) files;
+  Array.to_list files
+
+(** Do not raise. *)
+let is_dir p = try Sys.is_directory p with Sys_error _ -> false
diff --git a/ocsigen-dune-rules/ocsigen-ppx-client/dune b/ocsigen-dune-rules/ocsigen-ppx-client/dune
new file mode 100644
index 00000000..ff7a6d26
--- /dev/null
+++ b/ocsigen-dune-rules/ocsigen-ppx-client/dune
@@ -0,0 +1,5 @@
+(executable
+ (public_name ocsigen-ppx-client)
+ (package ocsigen-dune-rules)
+ (name main)
+ (libraries ocsigen-ppx-rpc eliom.ppx.client))
diff --git a/ocsigen-dune-rules/ocsigen-ppx-client/main.ml b/ocsigen-dune-rules/ocsigen-ppx-client/main.ml
new file mode 100644
index 00000000..e3cba404
--- /dev/null
+++ b/ocsigen-dune-rules/ocsigen-ppx-client/main.ml
@@ -0,0 +1 @@
+let () = Ppxlib.Driver.standalone ()
diff --git a/ocsigen-dune-rules/test/dune b/ocsigen-dune-rules/test/dune
new file mode 100644
index 00000000..58b3ec1e
--- /dev/null
+++ b/ocsigen-dune-rules/test/dune
@@ -0,0 +1,2 @@
+(cram
+ (deps %{bin:ocsigen-dune-rules}))
diff --git a/ocsigen-dune-rules/test/rules.t/a.eliom b/ocsigen-dune-rules/test/rules.t/a.eliom
new file mode 100644
index 00000000..e69de29b
diff --git a/ocsigen-dune-rules/test/rules.t/b.eliom b/ocsigen-dune-rules/test/rules.t/b.eliom
new file mode 100644
index 00000000..e69de29b
diff --git a/ocsigen-dune-rules/test/rules.t/b.eliomi b/ocsigen-dune-rules/test/rules.t/b.eliomi
new file mode 100644
index 00000000..e69de29b
diff --git a/ocsigen-dune-rules/test/rules.t/not_eliom.ml b/ocsigen-dune-rules/test/rules.t/not_eliom.ml
new file mode 100644
index 00000000..e69de29b
diff --git a/ocsigen-dune-rules/test/rules.t/run.t b/ocsigen-dune-rules/test/rules.t/run.t
new file mode 100644
index 00000000..cd8b0a53
--- /dev/null
+++ b/ocsigen-dune-rules/test/rules.t/run.t
@@ -0,0 +1,13 @@
+  $ ocsigen-dune-rules .
+  (rule
+   (with-stdout-to a.eliom
+    (chdir %{workspace_root}
+     (run ocsigen-ppx-client -as-pp -loc-filename %{dep:../a.eliom} --impl -server-cmo %{cmo:../a} %{dep:../a.eliom}))))
+  (rule
+   (with-stdout-to b.eliom
+    (chdir %{workspace_root}
+     (run ocsigen-ppx-client -as-pp -loc-filename %{dep:../b.eliom} --impl -server-cmo %{cmo:../b} %{dep:../b.eliom}))))
+  (rule
+   (with-stdout-to b.eliomi
+    (chdir %{workspace_root}
+     (run ocsigen-ppx-client -as-pp -loc-filename %{dep:../b.eliomi} --intf %{dep:../b.eliomi}))))
diff --git a/ocsigen-dune-rules/test/rules.t/subdir/.keep b/ocsigen-dune-rules/test/rules.t/subdir/.keep
new file mode 100644
index 00000000..e69de29b
diff --git a/ocsigen-toolkit.install b/ocsigen-toolkit.install
deleted file mode 100644
index f79e6bcd..00000000
--- a/ocsigen-toolkit.install
+++ /dev/null
@@ -1,16 +0,0 @@
-share: [
-  "css/ot_carousel.css"         {"css/ot_carousel.css"}
-  "css/ot_spinner.css"          {"css/ot_spinner.css"}
-  "css/ot_popup.css"            {"css/ot_popup.css"}
-  "css/ot_datetime.css"         {"css/ot_datetime.css"}
-  "css/ot_picture_uploader.css" {"css/ot_picture_uploader.css"}
-  "css/ot_icons.css"            {"css/ot_icons.css"}
-  "css/ot_drawer.css"           {"css/ot_drawer.css"}
-  "css/ot_buttons.css"          {"css/ot_buttons.css"}
-  "css/ot_sticky.css"           {"css/ot_sticky.css"}
-  "css/ot_page_transition.css"  {"css/ot_page_transition.css"}
-  "css/ot_color_picker.css"     {"css/ot_color_picker.css"}
-  "css/ot_pull_to_refresh.css"  {"css/ot_pull_to_refresh.css"}
-  "css/ot_tongue.css"           {"css/ot_tongue.css"}
-  "css/ot_form.css"             {"css/ot_form.css"}
-]
diff --git a/ocsigen-toolkit.opam b/ocsigen-toolkit.opam
new file mode 100644
index 00000000..fc5e4e42
--- /dev/null
+++ b/ocsigen-toolkit.opam
@@ -0,0 +1,37 @@
+# This file is generated by dune, edit dune-project instead
+opam-version: "2.0"
+synopsis:
+  "Reusable UI components for Eliom applications (client only, or client-server)"
+description:
+  "The Ocsigen Toolkit is a set of user interface widgets that facilitate the development of Eliom applications."
+maintainer: ["dev@ocsigen.org"]
+authors: ["dev@ocsigen.org"]
+license: "LGPL-2.1-only WITH OCaml-LGPL-linking-exception"
+homepage: "http://www.ocsigen.org"
+bug-reports: "https://github.com/ocsigen/ocsigen-toolkit/issues"
+depends: [
+  "dune" {>= "3.18"}
+  "ocaml" {>= "4.08.0"}
+  "js_of_ocaml" {>= "6.0.0"}
+  "eliom" {>= "11.0.0"}
+  "calendar" {>= "2.0.0"}
+  "cmdliner"
+  "ocsigen-ppx-rpc"
+  "odoc" {with-doc}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+]
+dev-repo: "git+https://github.com/ocsigen/ocsigen-toolkit.git"
+x-maintenance-intent: ["(latest)"]
diff --git a/opam b/opam
deleted file mode 100644
index 60e033be..00000000
--- a/opam
+++ /dev/null
@@ -1,21 +0,0 @@
-opam-version: "2.0"
-name: "ocsigen-toolkit"
-version: "4.2.0"
-maintainer: "dev@ocsigen.org"
-synopsis: "Reusable UI components for Eliom applications (client only, or client-server)"
-description: "The Ocsigen Toolkit is a set of user interface widgets that facilitate the development of Eliom applications."
-authors: "dev@ocsigen.org"
-homepage: "http://www.ocsigen.org"
-bug-reports: "https://github.com/ocsigen/ocsigen-toolkit/issues/"
-dev-repo: "git+https://github.com/ocsigen/ocsigen-toolkit.git"
-license: "LGPL-2.1-only WITH OCaml-LGPL-linking-exception"
-build: [ make "-j%{jobs}%" ]
-install: [ make "install" ]
-available: arch != "x86_32" & arch != "arm32"
-depends: [
-  "ocaml" {>= "4.08.0"}
-  "js_of_ocaml" {>= "6.0.0"}
-  "eliom" {>= "11.0.0"}
-  "calendar" {>= "2.0.0"}
-]
-x-maintenance-intent: ["(latest)" ]
diff --git a/src/widgets/dune b/src/widgets/dune
new file mode 100644
index 00000000..5f6f40ed
--- /dev/null
+++ b/src/widgets/dune
@@ -0,0 +1,39 @@
+(env
+ (_
+  (flags
+   (:standard -w +A-4-9-16-27-32-33-39-44-48-60-70))))
+
+(library
+ (public_name ocsigen-toolkit.server)
+ (name widgets_server)
+ (modes byte native)
+ (wrapped false)
+ (preprocess
+  (pps
+   eliom.ppx.server
+   lwt_ppx
+   js_of_ocaml-ppx_deriving_json
+   ocsigen-ppx-rpc
+   --rpc-raw))
+ (libraries eliom.server calendar js_of_ocaml))
+
+(subdir
+ client
+ (library
+  (public_name ocsigen-toolkit.client)
+  (name widgets_client)
+  (modes byte)
+  (wrapped false)
+  (preprocess
+   (pps js_of_ocaml-ppx lwt_ppx js_of_ocaml-ppx_deriving_json))
+  (libraries eliom.client calendar js_of_ocaml js_of_ocaml-lwt))
+ (dynamic_include ../dune.client))
+
+(rule
+ (deps
+  (glob_files *.eliom)
+  (glob_files *.eliomi))
+ (action
+  (with-stdout-to
+   dune.client
+   (run ocsigen-dune-rules .))))
diff --git a/src/widgets/ot_calendar.eliom b/src/widgets/ot_calendar.eliom
index 4f0efde3..19259d10 100644
--- a/src/widgets/ot_calendar.eliom
+++ b/src/widgets/ot_calendar.eliom
@@ -582,13 +582,15 @@ let%server make :
    ?button_labels
    ?intl
    () ->
-  C.node
-    [%client
-      (make ?init:~%init ?highlight:~%highlight
-         ?click_non_highlighted:~%click_non_highlighted ?update:~%update
-         ?action:~%action ?period:~%period ?intl:~%intl
-         ?button_labels:~%button_labels ()
-       : [> `Div] elt)]
+  (C.node
+     [%client
+       (make ?init:~%init ?highlight:~%highlight
+          ?click_non_highlighted:~%click_non_highlighted ?update:~%update
+          ?action:~%action ?period:~%period ?intl:~%intl
+          ?button_labels:~%button_labels ()
+        : [> `Div] elt)]
+    : [`Div] elt
+    :> [> `Div] elt)
 
 let%shared make_date_picker ?init ?update ?button_labels ?intl ?period () =
   let init =
diff --git a/src/widgets/ot_carousel.eliom b/src/widgets/ot_carousel.eliom
index fd76dc66..4c7fe31c 100644
--- a/src/widgets/ot_carousel.eliom
+++ b/src/widgets/ot_carousel.eliom
@@ -972,6 +972,9 @@ let%shared
       ~pos
       content
   =
+  let change =
+    (change :> ([`Prev | `Goto of int] -> unit) Eliom_client_value.t)
+  in
   Form.button_no_value ~button_type:`Button
     ~a:
       (R.a_class (Eliom_shared.React.S.map [%shared fun p -> blur (p = 0)] pos)
@@ -997,6 +1000,9 @@ let%shared
       ~length
       content
   =
+  let change =
+    (change :> ([`Next | `Goto of int] -> unit) Eliom_client_value.t)
+  in
   Form.button_no_value ~button_type:`Button
     ~a:
       (R.a_class
diff --git a/src/widgets/ot_color_picker.eliom b/src/widgets/ot_color_picker.eliom
index a45620a8..c061fd66 100644
--- a/src/widgets/ot_color_picker.eliom
+++ b/src/widgets/ot_color_picker.eliom
@@ -21,6 +21,7 @@
 
 [%%shared.start]
 
+open Eliom_content.Html
 open Eliom_shared.React.S.Infix
 
 let hsv_to_rgb h s v =
@@ -46,7 +47,6 @@ let rgb_to_css (r, g, b) =
     (int_of_float b)
 
 let display_hue_selector ~setter (sel_hue, sel_sat, sel_ltn) =
-  let open Eliom_content.Html in
   let dim = 111 in
   let irange = Array.init dim (fun x -> x) in
   let step = 360.0 /. float_of_int dim in
@@ -84,7 +84,6 @@ let display_hue_selector ~setter (sel_hue, sel_sat, sel_ltn) =
   * TODO: use a CSS3 gradient in each cell to make the grid look smoother
   *)
 let display_sl_grid ~setter (sel_hue, sel_sat, sel_ltn) =
-  let open Eliom_content.Html in
   let hue = float_of_int sel_hue in
   let dim = 51 in
   let irange = Array.init (dim * dim) (fun x -> x) in
@@ -130,19 +129,16 @@ let display_sl_grid ~setter (sel_hue, sel_sat, sel_ltn) =
   D.(div ~a:[a_class ["ot-color-picker-sl-picker"]] (Array.to_list rows))
 
 let display_aux ?(a = []) ~setter sel =
-  let open Eliom_content.Html in
   D.div
     ~a:(D.a_class ["ot-color-picker"] :: a)
     [display_hue_selector ~setter sel; display_sl_grid ~setter sel]
 
 let display ?a cp_sig =
   let setter = snd cp_sig in
-  fst cp_sig
-  >|= [%shared display_aux ?a:~%a ~setter:~%setter]
-  |> Eliom_content.Html.R.node
+  fst cp_sig >|= [%shared display_aux ?a:~%a ~setter:~%setter] |> R.node
 
 let make
-      ?a
+      ?(a : [< Html_types.div_attrib > `Class] attrib list option)
       ?hsv
       ?(update = [%client (React.E.never : (int * float * float) React.E.t)])
       ()
@@ -150,13 +146,13 @@ let make
   let ((cp_sig, cp_set) as cp_react) =
     Eliom_shared.React.S.create (Option.value hsv ~default:(255, 1.0, 0.0))
   in
+  let a = (a :> Html_types.div_attrib attrib list option) in
   let elt, signal = display ?a cp_react, cp_sig in
-  let elt = Eliom_content.Html.D.div [elt] in
+  let elt = D.div [elt] in
   ignore
     [%client
       (* /!\ How to avoid the effectful signal ? *)
-      (Eliom_lib.Dom_reference.retain
-         (Eliom_content.Html.To_dom.of_element ~%elt)
+      (Eliom_lib.Dom_reference.retain (To_dom.of_element ~%elt)
          ~keep:
            (React.E.map (fun update -> ~%cp_set update) ~%update
             : unit React.event)
diff --git a/src/widgets/ot_form.eliom b/src/widgets/ot_form.eliom
index 42b0d9f6..7a80c40f 100644
--- a/src/widgets/ot_form.eliom
+++ b/src/widgets/ot_form.eliom
@@ -690,7 +690,8 @@ let%shared password_input ?(a = []) ?placeholder () =
 
 (* -- Password toggle (non-reactive) ------------------------------ *)
 
-let%shared password_toggle (inp : [< Html_types.input] elt) =
+let%shared password_toggle inp =
+  let inp = (inp : [< Html_types.input] elt :> Html_types.input elt) in
   let toggle_icon =
     D.span ~a:[a_class ["ot-password-toggle-show"]] []
   in
diff --git a/src/widgets/ot_picture_uploader.eliom b/src/widgets/ot_picture_uploader.eliom
index 9d31d45d..c01140a5 100644
--- a/src/widgets/ot_picture_uploader.eliom
+++ b/src/widgets/ot_picture_uploader.eliom
@@ -457,7 +457,7 @@ let%client ocaml_service_upload ~service ~arg ?progress ?cropping file =
 
 let%client do_submit input ?progress ?cropping ~upload () =
   process_file input @@ fun file ->
-  let* _ = upload ?progress ?cropping file in
+  let* () = upload ?progress ?cropping file in
   Lwt.return_unit
 
 let%client
@@ -503,7 +503,7 @@ let%shared
       ?crop
       ?input:(input_a, input_content = [], [])
       ?submit:(submit_a, submit_content = [], [])
-      (upload : 'a upload)
+      (upload : unit upload)
   =
   let preview = preview () in
   let input, input_label = input ~a:input_a input_content in
diff --git a/src/widgets/ot_picture_uploader.eliomi b/src/widgets/ot_picture_uploader.eliomi
index df129b10..933d6fbe 100644
--- a/src/widgets/ot_picture_uploader.eliomi
+++ b/src/widgets/ot_picture_uploader.eliomi
@@ -87,7 +87,7 @@ val do_submit :
    Dom_html.inputElement Js.t Eliom_client_value.t
   -> ?progress:(int -> int -> unit)
   -> ?cropping:cropping
-  -> upload:'a upload
+  -> upload:unit upload
   -> unit
   -> unit Lwt.t
 (** [ do_submit input ?cropping ~upload () ]
@@ -99,7 +99,7 @@ val bind_submit :
    Dom_html.inputElement Js.t Eliom_client_value.t
   -> #Dom_html.eventTarget Js.t Eliom_client_value.t
   -> ?cropping:cropping
-  -> upload:'a upload
+  -> upload:unit upload
   -> after_submit:(unit -> unit Lwt.t)
   -> unit
   -> unit
@@ -113,7 +113,7 @@ val bind :
   -> preview:Dom_html.imageElement Js.t
   -> ?crop:(unit -> unit) * cropping
   -> submit:#Dom_html.eventTarget Js.t Eliom_client_value.t
-  -> upload:'a upload
+  -> upload:unit upload
   -> after_submit:(unit -> unit Lwt.t)
   -> unit
   -> unit
@@ -150,7 +150,7 @@ val mk_form :
   -> ?submit:
        [< Html_types.button_attrib > `Class] Eliom_content.Html.attrib list
        * [< Html_types.button_content_fun] Eliom_content.Html.elt list
-  -> 'a upload
+  -> unit upload
   -> [> `Form] Eliom_content.Html.elt Lwt.t
 (** Ready-to-use form. Customizable with
     [input], the input button content, [submit], the submit button content.
diff --git a/src/widgets/ot_pulltorefresh.eliom b/src/widgets/ot_pulltorefresh.eliom
index 23aaf803..397bc07d 100644
--- a/src/widgets/ot_pulltorefresh.eliom
+++ b/src/widgets/ot_pulltorefresh.eliom
@@ -4,10 +4,11 @@ type state = Pulling | Ready | Loading | Succeeded | Failed
 
 [%%client open Eliom_content.Html]
 
-open Eliom_content.Html.D
+module H = Eliom_content.Html
+open H.D
 
-let%shared default_header =
-  let open Eliom_content.Html in
+let%shared default_header : state option -> [> `Div] H.elt list =
+  let open H in
   function
   | Some Loading -> [F.div ~a:[F.a_class ["ot-icon-animation-spinning"]] []]
   | _ -> []
@@ -19,7 +20,7 @@ open Lwt.Syntax
 module type CONF = sig
   val dragThreshold : float
   val scale : float
-  val container : Html_types.div Eliom_content.Html.D.elt
+  val container : Html_types.div H.D.elt
   val set_state : ?step:React.step -> state option -> unit
   val timeout : float
   val afterPull : unit -> bool Lwt.t
@@ -168,13 +169,13 @@ module Make (Conf : CONF) = struct
 end]
 
 let make
-      ?(a = [])
+      ?(a : [< Html_types.div_attrib > `Class] H.attrib list = [])
       ?(app_only = true)
       ?(scale = 5.)
       ?(dragThreshold = 80.)
       ?(refresh_timeout = 20.)
       ?(header = [%shared default_header])
-      ~content
+      ~(content : Html_types.div_content H.elt)
       (afterPull : (unit -> bool Lwt.t) Eliom_client_value.t)
   =
   if app_only && not (Eliom_client.is_client_app ())
@@ -182,10 +183,10 @@ let make
   else
     let state_s, set_state = Eliom_shared.React.S.create None in
     let headContainer =
-      Eliom_content.Html.R.node
+      H.R.node
       @@ Eliom_shared.React.S.map
            [%shared
-             let open Eliom_content.Html in
+             let open H in
              fun s ->
                D.div ~a:[D.a_class ["ot-pull-refresh-head-container"]]
                @@ Eliom_shared.Value.local ~%header
@@ -209,5 +210,6 @@ let make
          let module Ptr = Make (Ptr_conf) in
          Ptr.init ()
          : unit)];
-    let open Eliom_content.Html in
-    F.div ~a:(F.a_class ["ot-pull-refresh-wrapper"] :: a) [container]
+    let open H in
+    (F.div ~a:(F.a_class ["ot-pull-refresh-wrapper"] :: a) [container]
+      :> [> `Div] elt)
diff --git a/src/widgets/ot_pulltorefresh.eliomi b/src/widgets/ot_pulltorefresh.eliomi
index c45d0054..331d5b42 100644
--- a/src/widgets/ot_pulltorefresh.eliomi
+++ b/src/widgets/ot_pulltorefresh.eliomi
@@ -20,13 +20,11 @@ val make :
   -> ?dragThreshold:float
   -> ?refresh_timeout:float
   -> ?header:
-       (state option
-        -> ([< Html_types.div_content_fun > `Div] as 'a) Eliom_content.Html.elt
-             list)
+       (state option -> Html_types.div_content Eliom_content.Html.elt list)
          Eliom_shared.Value.t
-  -> content:'a Eliom_content.Html.elt
+  -> content:Html_types.div_content Eliom_content.Html.elt
   -> (unit -> bool Lwt.t) Eliom_client_value.t
-  -> 'a Eliom_content.Html.elt
+  -> [> `Div] Eliom_content.Html.elt
 (**
    Creates a pull-to-refresh container from an html element.
    [?a] is the attribute array of the returned element
diff --git a/src/widgets/ot_swipe.eliom b/src/widgets/ot_swipe.eliom
index d17f739f..3112f344 100644
--- a/src/widgets/ot_swipe.eliom
+++ b/src/widgets/ot_swipe.eliom
@@ -107,11 +107,11 @@ let%shared
          (Dom_html.touchEvent Js.t -> int -> unit) Eliom_client_value.t option)
       ?(onend :
          (Dom_html.touchEvent Js.t -> int -> unit) Eliom_client_value.t option)
-      (elt : _ elt)
+      (elt : Html_types.div_content elt)
   =
   ignore
     [%client
-      (let elt = ~%elt in
+      (let elt = (~%elt :> Html_types.div_content elt) in
        let elt' = To_dom.of_element elt in
        let startx =
          ref 0.
diff --git a/src/widgets/ot_swipe.eliomi b/src/widgets/ot_swipe.eliomi
index e3103a21..7ba988b7 100644
--- a/src/widgets/ot_swipe.eliomi
+++ b/src/widgets/ot_swipe.eliomi
@@ -11,7 +11,7 @@ val bind :
   -> ?onstart:(Dom_html.touchEvent Js.t -> int -> unit) Eliom_client_value.t
   -> ?onmove:(Dom_html.touchEvent Js.t -> int -> unit) Eliom_client_value.t
   -> ?onend:(Dom_html.touchEvent Js.t -> int -> unit) Eliom_client_value.t
-  -> 'a Eliom_content.Html.elt
+  -> Html_types.div_content Eliom_content.Html.elt
   -> unit
 (**
    [bind ~compute_final_pos elt] makes [elt] left-right
diff --git a/src/widgets/ot_tongue.eliomi b/src/widgets/ot_tongue.eliomi
index 49e5de53..025eb61d 100644
--- a/src/widgets/ot_tongue.eliomi
+++ b/src/widgets/ot_tongue.eliomi
@@ -25,7 +25,7 @@ val tongue :
   -> ?side:[`Bottom | `Left | `Right | `Top]
   -> ?stops:stop list
   -> ?init:simple_stop
-  -> ?handle:[> `Div] Eliom_content.Html.elt
+  -> ?handle:Html_types.div_content Eliom_content.Html.elt
   -> ?update:simple_stop React.event Eliom_client_value.t
   -> [< Html_types.div_content_fun] Eliom_content.Html.elt list
   -> tongue