diff --git a/src/core/core-upgrade.c b/src/core/core-upgrade.c
index b512969d0..49f3c64dd 100644
--- a/src/core/core-upgrade.c
+++ b/src/core/core-upgrade.c
@@ -535,6 +535,8 @@ upgrade_weechat_read_buffer (struct t_infolist *infolist)
         infolist_integer (infolist, "time_for_each_line");
 
     /* input */
+    gui_buffer_set_input_prompt (
+        ptr_buffer, infolist_string (infolist, "input_prompt"));
     ptr_buffer->input = infolist_integer (infolist, "input");
     ptr_buffer->input_get_any_user_data =
         infolist_integer (infolist, "input_get_any_user_data");
diff --git a/src/gui/gui-buffer.h b/src/gui/gui-buffer.h
index ed0974b7b..bad58bcda 100644
--- a/src/gui/gui-buffer.h
+++ b/src/gui/gui-buffer.h
@@ -385,6 +385,8 @@ extern void gui_buffer_set_highlight_tags (struct t_gui_buffer *buffer,
                                            const char *new_tags);
 extern void gui_buffer_set_hotlist_max_level_nicks (struct t_gui_buffer *buffer,
                                                     const char *new_hotlist_max_level_nicks);
+extern void gui_buffer_set_input_prompt (struct t_gui_buffer *buffer,
+                                         const char *input_prompt);
 extern void gui_buffer_set (struct t_gui_buffer *buffer, const char *property,
                             const char *value);
 extern void gui_buffer_set_pointer (struct t_gui_buffer *buffer,
diff --git a/tests/unit/gui/test-gui-buffer.cpp b/tests/unit/gui/test-gui-buffer.cpp
index b33711143..dea97f3a2 100644
--- a/tests/unit/gui/test-gui-buffer.cpp
+++ b/tests/unit/gui/test-gui-buffer.cpp
@@ -42,8 +42,6 @@ extern int gui_buffer_user_input_cb (const void *pointer, void *data,
                                      const char *input_data);
 extern int gui_buffer_user_close_cb (const void *pointer, void *data,
                                      struct t_gui_buffer *buffer);
-extern void gui_buffer_set_input_prompt (struct t_gui_buffer *buffer,
-                                         const char *input_prompt);
 extern void gui_buffer_set_short_name (struct t_gui_buffer *buffer,
                                        const char *short_name);
 extern void gui_buffer_set_highlight_words_list (struct t_gui_buffer *buffer,