diff --git a/ChangeLog b/ChangeLog
index e331adf1..3de5054d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -11,6 +11,9 @@
    Fix loading custom filetype settings (e.g. default extension).
    Add note about using GeanyFiletype pointer instead of filetype_id
    for function arguments.
+ * src/filetypes.c:
+   Prevent adding entries for both system and user custom filetype
+   files.
 
 
 2009-08-11  Nick Treleaven  <nick(dot)treleaven(at)btinternet(dot)com>
diff --git a/src/filetypes.c b/src/filetypes.c
index 7ad1af87..79f73a50 100644
--- a/src/filetypes.c
+++ b/src/filetypes.c
@@ -670,6 +670,9 @@ static void add_custom_filetype(const gchar *filename)
 
 	*dot = 0x0;
 
+	if (g_hash_table_lookup(filetypes_hash, fn))
+		return;
+
 	geany_debug("Adding filetype %s.", fn);
 	ft = filetype_new();
 	ft->name = g_strdup(fn);