--- a/exif/main.c
+++ b/exif/main.c
@@ -396,6 +396,10 @@
     return 0;
   }
 
+  if (tag_string && ifd_string == NULL) {
+      ifd_string = "EXIF";
+  }
+
 	if (ifd_string) {
 		ifd = exif_ifd_from_string (ifd_string);
 		if ((ifd < EXIF_IFD_0) || (ifd >= EXIF_IFD_COUNT) ||
