diff --git a/ChangeLog b/ChangeLog
index 52b3d6d3c..b7b30af6f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,6 +7,8 @@ v0.3.6-dev, 2011-08-02
 Version 0.3.6 (under dev!)
 --------------------------
 
+* core: fix crash when invalid UTF-8 chars are inserted in command line
+  (bug #33471)
 * core: stop horizontal bar scroll at the end of content (for bars with
   horizontal filling) (bug #27908)
 * core: fix crash when building hashtable string with keys and values
diff --git a/src/gui/gui-input.c b/src/gui/gui-input.c
index 072df0368..e8cfb0a70 100644
--- a/src/gui/gui-input.c
+++ b/src/gui/gui-input.c
@@ -81,21 +81,30 @@ void
 gui_input_replace_input (struct t_gui_buffer *buffer, const char *new_input)
 {
     int size, length;
+    char *input_utf8;
     
-    size = strlen (new_input);
-    length = utf8_strlen (new_input);
-    
-    /* compute new buffer size */
-    buffer->input_buffer_size = size;
-    buffer->input_buffer_length = length;
-    gui_input_optimize_size (buffer);
-    
-    /* copy new string to input */
-    strcpy (buffer->input_buffer, new_input);
-    
-    /* move cursor to the end of new input if it is now after the end */
-    if (buffer->input_buffer_pos > buffer->input_buffer_length)
-        buffer->input_buffer_pos = buffer->input_buffer_length;
+    input_utf8 = strdup (new_input);
+    if (input_utf8)
+    {
+        utf8_normalize (input_utf8, '?');
+        
+        size = strlen (input_utf8);
+        length = utf8_strlen (input_utf8);
+        
+        /* compute new buffer size */
+        buffer->input_buffer_size = size;
+        buffer->input_buffer_length = length;
+        gui_input_optimize_size (buffer);
+        
+        /* copy new string to input */
+        strcpy (buffer->input_buffer, input_utf8);
+        
+        /* move cursor to the end of new input if it is now after the end */
+        if (buffer->input_buffer_pos > buffer->input_buffer_length)
+            buffer->input_buffer_pos = buffer->input_buffer_length;
+        
+        free (input_utf8);
+    }
 }
 
 /*
@@ -196,15 +205,21 @@ gui_input_insert_string (struct t_gui_buffer *buffer, const char *string,
                          int pos)
 {
     int size, length;
-    char *ptr_start;
+    char *string_utf8, *ptr_start;
     
     if (buffer->input)
     {
+        string_utf8 = strdup (string);
+        if (!string_utf8)
+            return 0;
+        
         if (pos == -1)
             pos = buffer->input_buffer_pos;
         
-        size = strlen (string);
-        length = utf8_strlen (string);
+        utf8_normalize (string_utf8, '?');
+        
+        size = strlen (string_utf8);
+        length = utf8_strlen (string_utf8);
         
         /* increase buffer size */
         buffer->input_buffer_size += size;
@@ -218,10 +233,12 @@ gui_input_insert_string (struct t_gui_buffer *buffer, const char *string,
         
         /* insert new string */
         ptr_start = utf8_add_offset (buffer->input_buffer, pos);
-        strncpy (ptr_start, string, size);
+        strncpy (ptr_start, string_utf8, size);
         
         buffer->input_buffer_pos += length;
         
+        free (string_utf8);
+        
         return length;
     }
     return 0;