diff --git a/src/hotplug-sniffer/shell-mime-sniffer.c b/src/hotplug-sniffer/shell-mime-sniffer.c
index 6c56ecbaf..7a1c1fe89 100644
--- a/src/hotplug-sniffer/shell-mime-sniffer.c
+++ b/src/hotplug-sniffer/shell-mime-sniffer.c
@@ -253,7 +253,9 @@ deep_count_one (DeepCountState *state,
   else
     {
       content_type = g_file_info_get_content_type (info);
-      add_content_type_to_cache (state, content_type);
+
+      if (content_type)
+        add_content_type_to_cache (state, content_type);
     }
 }