diff --git a/util/hb-subset.cc b/util/hb-subset.cc
index 624bb1f75..b65bf3154 100644
--- a/util/hb-subset.cc
+++ b/util/hb-subset.cc
@@ -128,6 +128,8 @@ struct subset_main_t : option_parser_t, face_options_t, output_options_t<false>
       write_file (output_file, result);
       hb_blob_destroy (result);
     }
+    else if (hb_face_get_glyph_count (orig_face) == 0)
+      fail (false, "Invalid font file.");
 
     hb_face_destroy (new_face);
     if (preprocess)