diff --git a/workbench/libs/rexxsyslib/fillrexxmsg.c b/workbench/libs/rexxsyslib/fillrexxmsg.c
index b421d984944..a87a59d3eb5 100644
--- a/workbench/libs/rexxsyslib/fillrexxmsg.c
+++ b/workbench/libs/rexxsyslib/fillrexxmsg.c
@@ -66,7 +66,7 @@
 {
     AROS_LIBFUNC_INIT
     STRPTR args[16];
-    char number[20];
+    char number[32];
     ULONG i, j;
     
     for (i = 0; i < count; i++)
@@ -75,7 +75,7 @@
         if (mask & (1<<i))
         {
             /* Convert int to string */
-            sprintf(number, "%ld", (long)msgptr->rm_Args[i]);
+            snprintf(number, sizeof(number), "%ld", (long)msgptr->rm_Args[i]);
             args[i] = (STRPTR)CreateArgstring(number, strlen(number));
             
             /* Clean up if error in CreateArgstring */