diff --git a/gcc/config/c4x/c4x.h b/gcc/config/c4x/c4x.h
index a68e5e27e4f..4da3847a51e 100644
--- a/gcc/config/c4x/c4x.h
+++ b/gcc/config/c4x/c4x.h
@@ -29,6 +29,8 @@
 #define TARGET_CPU_CPP_BUILTINS()		\
   do						\
     {						\
+      /* ??? HACK.  We shouldn't have flag_inline_trees at all.  */ \
+      extern int flag_inline_trees;		\
       if (!TARGET_SMALL)			\
 	builtin_define ("_BIGMODEL");		\
       if (!TARGET_MEMPARM)			\