diff --git a/main/php.h b/main/php.h
index 5a5dd406171..2d22297d3ac 100644
--- a/main/php.h
+++ b/main/php.h
@@ -182,6 +182,7 @@ END_EXTERN_C()
 #undef strlcpy
 #define strlcpy php_strlcpy
 #define HAVE_STRLCPY 1
+#define USE_STRLCPY_PHP_IMPL 1
 #endif
 
 #ifndef HAVE_STRLCAT
@@ -191,6 +192,7 @@ END_EXTERN_C()
 #undef strlcat
 #define strlcat php_strlcat
 #define HAVE_STRLCAT 1
+#define USE_STRLCAT_PHP_IMPL 1
 #endif
 
 #ifndef HAVE_EXPLICIT_BZERO
diff --git a/main/strlcat.c b/main/strlcat.c
index a381b1433c1..d3c8972d68d 100644
--- a/main/strlcat.c
+++ b/main/strlcat.c
@@ -20,7 +20,7 @@
 
 #include "php.h"
 
-#ifndef HAVE_STRLCAT
+#ifdef USE_STRLCAT_PHP_IMPL
 
 /*     $OpenBSD: strlcat.c,v 1.17 2016/10/14 18:19:04 dtucker Exp $    */
 
diff --git a/main/strlcpy.c b/main/strlcpy.c
index 3e66140ef61..548dd9410b2 100644
--- a/main/strlcpy.c
+++ b/main/strlcpy.c
@@ -20,7 +20,7 @@
 
 #include "php.h"
 
-#ifndef HAVE_STRLCPY
+#ifdef USE_STRLCPY_PHP_IMPL
 
 /*     $OpenBSD: strlcpy.c,v 1.15 2016/10/16 17:37:39 dtucker Exp $    */