diff --git a/doc/en/weechat_plugin_api.en.txt b/doc/en/weechat_plugin_api.en.txt
index 159df6a8b..6806bcea6 100644
--- a/doc/en/weechat_plugin_api.en.txt
+++ b/doc/en/weechat_plugin_api.en.txt
@@ -1552,7 +1552,7 @@ Prototype:
 
 [source,C]
 ----------------------------------------
-void weechat_utf8_normalize (const char *string, char replacement);
+void weechat_utf8_normalize (char *string, char replacement);
 ----------------------------------------
 
 Arguments:
diff --git a/doc/fr/weechat_plugin_api.fr.txt b/doc/fr/weechat_plugin_api.fr.txt
index 6605a2ff4..931d3befb 100644
--- a/doc/fr/weechat_plugin_api.fr.txt
+++ b/doc/fr/weechat_plugin_api.fr.txt
@@ -1571,7 +1571,7 @@ Prototype :
 
 [source,C]
 ----------------------------------------
-void weechat_utf8_normalize (const char *string, char replacement);
+void weechat_utf8_normalize (char *string, char replacement);
 ----------------------------------------
 
 Paramètres :
diff --git a/doc/it/weechat_plugin_api.it.txt b/doc/it/weechat_plugin_api.it.txt
index aff4db708..a83b1f754 100644
--- a/doc/it/weechat_plugin_api.it.txt
+++ b/doc/it/weechat_plugin_api.it.txt
@@ -1531,7 +1531,7 @@ Prototipo:
 
 [source,C]
 ----------------------------------------
-void weechat_utf8_normalize (const char *string, char replacement);
+void weechat_utf8_normalize (char *string, char replacement);
 ----------------------------------------
 
 Argomenti:
diff --git a/src/core/wee-utf8.c b/src/core/wee-utf8.c
index bb4c6ac54..1ef32542e 100644
--- a/src/core/wee-utf8.c
+++ b/src/core/wee-utf8.c
@@ -134,7 +134,7 @@ utf8_is_valid (const char *string, char **error)
  */
 
 void
-utf8_normalize (const char *string, char replacement)
+utf8_normalize (char *string, char replacement)
 {
     char *error;
     
diff --git a/src/core/wee-utf8.h b/src/core/wee-utf8.h
index 0f7a4244a..51a721143 100644
--- a/src/core/wee-utf8.h
+++ b/src/core/wee-utf8.h
@@ -35,7 +35,7 @@ extern int local_utf8;
 extern void utf8_init ();
 extern int utf8_has_8bits (const char *string);
 extern int utf8_is_valid (const char *string, char **error);
-extern void utf8_normalize (const char *string, char replacement);
+extern void utf8_normalize (char *string, char replacement);
 extern char *utf8_prev_char (const char *string_start, const char *string);
 extern char *utf8_next_char (const char *string);
 extern int utf8_char_int (const char *string);
diff --git a/src/plugins/weechat-plugin.h b/src/plugins/weechat-plugin.h
index 99eead9ed..ffe979d80 100644
--- a/src/plugins/weechat-plugin.h
+++ b/src/plugins/weechat-plugin.h
@@ -46,7 +46,7 @@ struct timeval;
  */
 
 /* API version (used to check that plugin has same API and can be loaded) */
-#define WEECHAT_PLUGIN_API_VERSION "20110726-01"
+#define WEECHAT_PLUGIN_API_VERSION "20110802-01"
 
 /* macros for defining plugin infos */
 #define WEECHAT_PLUGIN_NAME(__name)                                     \
@@ -212,7 +212,7 @@ struct t_weechat_plugin
     /* UTF-8 strings */
     int (*utf8_has_8bits) (const char *string);
     int (*utf8_is_valid) (const char *string, char **error);
-    void (*utf8_normalize) (const char *string, char replacement);
+    void (*utf8_normalize) (char *string, char replacement);
     char *(*utf8_prev_char) (const char *string_start, const char *string);
     char *(*utf8_next_char) (const char *string);
     int (*utf8_char_int) (const char *string);