diff --git a/cmake/re-config.cmake b/cmake/re-config.cmake
index ff3af9de4..8dea2f6cb 100644
--- a/cmake/re-config.cmake
+++ b/cmake/re-config.cmake
@@ -30,6 +30,19 @@ if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
         FORCE)
 endif()
 
+if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
+  list(APPEND RE_DEFINITIONS DARWIN)
+elseif(${CMAKE_SYSTEM_NAME} MATCHES "iOS")
+  list(APPEND RE_DEFINITIONS DARWIN)
+elseif(${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD")
+  list(APPEND RE_DEFINITIONS FREEBSD)
+elseif(${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
+  list(APPEND RE_DEFINITIONS OPENBSD)
+elseif(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
+  list(APPEND RE_DEFINITIONS LINUX)
+  SET(CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS} -D_GNU_SOURCE")
+endif()
+
 check_symbol_exists(LIBRESSL_VERSION_NUMBER "${OPENSSL_INCLUDE_DIR}/openssl/opensslv.h" HAVE_LIBRESSL)
 if(USE_TLS1_3_PHA AND NOT HAVE_LIBRESSL AND NOT USE_MBEDTLS AND OPENSSL_FOUND)
   list(APPEND RE_DEFINITIONS HAVE_TLS1_3_POST_HANDSHAKE_AUTH)
@@ -80,6 +93,11 @@ else()
   set(Backtrace_LIBRARIES)
 endif()
 
+check_symbol_exists(memrchr "string.h" HAVE_MEMRCHR)
+if(HAVE_MEMRCHR)
+  list(APPEND RE_DEFINITIONS HAVE_MEMRCHR)
+endif()
+
 check_function_exists(thrd_create HAVE_THREADS_FUN)
 check_include_file(threads.h HAVE_THREADS_H)
 if(HAVE_THREADS_FUN AND HAVE_THREADS_H)
@@ -215,17 +233,6 @@ if(USE_TRACE)
   )
 endif()
 
-if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
-  list(APPEND RE_DEFINITIONS DARWIN)
-elseif(${CMAKE_SYSTEM_NAME} MATCHES "iOS")
-  list(APPEND RE_DEFINITIONS DARWIN)
-elseif(${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD")
-  list(APPEND RE_DEFINITIONS FREEBSD)
-elseif(${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
-  list(APPEND RE_DEFINITIONS OPENBSD)
-elseif(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
-  list(APPEND RE_DEFINITIONS LINUX)
-endif()
 
 
 list(APPEND RE_DEFINITIONS
diff --git a/src/fmt/pl.c b/src/fmt/pl.c
index a34eff2fa..523c3e582 100644
--- a/src/fmt/pl.c
+++ b/src/fmt/pl.c
@@ -761,18 +761,10 @@ int pl_casecmp(const struct pl *pl1, const struct pl *pl2)
  */
 const char *pl_strchr(const struct pl *pl, char c)
 {
-	const char *p, *end;
-
-	if (!pl)
+	if (!pl_isset(pl))
 		return NULL;
 
-	end = pl->p + pl->l;
-	for (p = pl->p; p < end; p++) {
-		if (*p == c)
-			return p;
-	}
-
-	return NULL;
+	return memchr(pl->p, c, pl->l);
 }
 
 
@@ -786,6 +778,11 @@ const char *pl_strchr(const struct pl *pl, char c)
  */
 const char *pl_strrchr(const struct pl *pl, char c)
 {
+	if (!pl_isset(pl))
+		return NULL;
+#if HAVE_MEMRCHR
+	return memrchr(pl->p, c, pl->l);
+#else
 	const char *p, *end;
 
 	if (!pl_isset(pl))
@@ -798,6 +795,7 @@ const char *pl_strrchr(const struct pl *pl, char c)
 	}
 
 	return NULL;
+#endif
 }
 
 
@@ -821,13 +819,13 @@ const char *pl_strstr(const struct pl *pl, const char *str)
 	if (!len)
 		return pl->p;
 
-	for (size_t i = 0; i < pl->l; ++i) {
-		/*case rest of pl is not long enough*/
-		if (pl->l - i < len)
-			return NULL;
+	const char *p = pl->p;
+	const char *end = pl->p + pl->l - len;
 
-		if (!memcmp(pl->p + i, str, len))
-			return pl->p + i;
+	while ((p = memchr(p, *str, (size_t)(end - p) + 1)) != NULL) {
+		if (!memcmp(p, str, len))
+			return p;
+		++p;
 	}
 
 	return NULL;