diff --git a/ext/pcre/php_pcre.c b/ext/pcre/php_pcre.c
index b1ee89a8a49..7d34d9feb15 100644
--- a/ext/pcre/php_pcre.c
+++ b/ext/pcre/php_pcre.c
@@ -251,7 +251,7 @@ PHPAPI pcre_cache_entry* pcre_get_compiled_regex_cache(char *regex, int regex_le
 	char                *tmp = NULL;
 
 #if HAVE_SETLOCALE
-# ifdef PHP_WIN32 && ZTS
+# if defined(PHP_WIN32) && defined(ZTS)
 	_configthreadlocale(_ENABLE_PER_THREAD_LOCALE);
 # endif
 	locale = setlocale(LC_CTYPE, NULL);