diff --git a/gio/gcontenttype.c b/gio/gcontenttype.c
index 170bb4341..665668890 100644
--- a/gio/gcontenttype.c
+++ b/gio/gcontenttype.c
@@ -486,6 +486,7 @@ gchar *
 g_content_type_get_description (const gchar *type)
 {
   static GHashTable *type_comment_cache = NULL;
+  gchar *type_copy = NULL;
   gchar *comment;
 
   g_return_val_if_fail (type != NULL, NULL);
@@ -500,16 +501,21 @@ g_content_type_get_description (const gchar *type)
 
   comment = g_hash_table_lookup (type_comment_cache, type);
   comment = g_strdup (comment);
-  G_UNLOCK (gio_xdgmime);
 
   if (comment != NULL)
-    return comment;
+    {
+      G_UNLOCK (gio_xdgmime);
+      return comment;
+    }
 
-  comment = load_comment_for_mime (type);
+  type_copy = g_strdup (type);
 
+  G_UNLOCK (gio_xdgmime);
+  comment = load_comment_for_mime (type_copy);
   G_LOCK (gio_xdgmime);
+
   g_hash_table_insert (type_comment_cache,
-                       g_strdup (type),
+                       g_steal_pointer (&type_copy),
                        g_strdup (comment));
   G_UNLOCK (gio_xdgmime);