diff --git a/gcc/toplev.c b/gcc/toplev.c
index aa8f5e139725..8d9a1c2d8151 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -808,6 +808,7 @@ char *lang_options[] =
 
   /* This is for GNAT and is temporary.  */
   "-gnat",
+  "-I",
   0
 };