Avoid compiler warnings.
diff --git a/src/if_perl.xs b/src/if_perl.xs
index 5c0c8ea..1a83de4 100644
--- a/src/if_perl.xs
+++ b/src/if_perl.xs
@@ -696,7 +696,9 @@
     char	*script;
     STRLEN	length;
     SV		*sv;
+#ifdef HAVE_SANDBOX
     SV		*safe;
+#endif
 
     script = (char *)script_get(eap, eap->arg);
     if (eap->skip)