diff --git a/girepository.c b/girepository.c
index d56482ece..97f2627db 100644
--- a/girepository.c
+++ b/girepository.c
@@ -489,12 +489,17 @@ find_interface (gpointer key,
     {
       for (i = 1; i <= n_entries; i++)
 	{
+	  RegisteredTypeBlob *blob;
+
 	  entry = g_typelib_get_dir_entry (typelib, i);
-	  if (entry->blob_type < BLOB_TYPE_BOXED)
+	  if (!BLOB_IS_REGISTERED_TYPE (entry))
 	    continue;
-	  
-	  offset = *(guint32*)&typelib->data[entry->offset + 8];
-	  type = g_typelib_get_string (typelib, offset);
+
+	  blob = (RegisteredTypeBlob *)entry;
+	  if (!blob->gtype_name)
+	    continue;
+
+	  type = g_typelib_get_string (typelib, blob->gtype_name);
 	  if (strcmp (type, iface_data->type) == 0)
 	    {
 	      index = i;
diff --git a/gtypelib.h b/gtypelib.h
index b71322313..54bf0523c 100644
--- a/gtypelib.h
+++ b/gtypelib.h
@@ -45,6 +45,13 @@ enum
   BLOB_TYPE_UNION
 };
 
+#define BLOB_IS_REGISTERED_TYPE(blob)               \
+        ((blob)->blob_type == BLOB_TYPE_STRUCT ||   \
+         (blob)->blob_type == BLOB_TYPE_UNION  ||   \
+         (blob)->blob_type == BLOB_TYPE_ENUM   ||   \
+         (blob)->blob_type == BLOB_TYPE_OBJECT ||   \
+         (blob)->blob_type == BLOB_TYPE_INTERFACE)
+
 typedef struct
 {
   gchar   magic[16];