diff --git a/src/if_perl.xs b/src/if_perl.xs
index 099d386..fd9d3d7 100644
--- a/src/if_perl.xs
+++ b/src/if_perl.xs
@@ -47,6 +47,9 @@
 /* Work around for using MSVC and ActivePerl 5.18. */
 #ifdef _MSC_VER
 # define __inline__ __inline
+
+// Work around for using MSVC and Strawberry Perl 5.30.
+# define __builtin_expect(expr, val) (expr)
 #endif
 
 #ifdef __GNUC__