1 files changed, 1 insertions, 1 deletions
diff --git a/io.c b/io.c
index a958b0f276..6a4ca44bf4 100644
--- a/io.c
+++ b/io.c
@@ -7853,7 +7853,7 @@ rb_f_syscall(int argc, VALUE *argv)
 #else
     VALUE arg[8];
 #endif
-#if SIZEOF_VOIDP == 8 && HAVE___SYSCALL && SIZEOF_INT != 8 /* mainly *BSD */
+#if SIZEOF_VOIDP == 8 && defined(HAVE___SYSCALL) && SIZEOF_INT != 8 /* mainly *BSD */
 # define SYSCALL __syscall
 # define NUM2SYSCALLID(x) NUM2LONG(x)
 # define RETVAL2NUM(x) LONG2NUM(x)