diff --git a/ext/ereg/regex/regerror.c b/ext/ereg/regex/regerror.c
index 05737a462ce..1c66d4114e3 100644
--- a/ext/ereg/regex/regerror.c
+++ b/ext/ereg/regex/regerror.c
@@ -8,6 +8,7 @@
 #include "regex.h"
 #include "utils.h"
 #include "regerror.ih"
+#include "php.h"
 
 /*
  = #define	REG_OKAY	 0