diff --git a/sys/ia64/ia32/ia32_signal.c b/sys/ia64/ia32/ia32_signal.c
index 31bce97d9fce..913cd15accad 100644
--- a/sys/ia64/ia32/ia32_signal.c
+++ b/sys/ia64/ia32/ia32_signal.c
@@ -26,6 +26,8 @@
  * $FreeBSD$
  */
 
+#include "opt_compat.h"
+
 #define __ELF_WORD_SIZE 32
 
 #include <sys/param.h>