diff --git a/php/ChangeLog b/php/ChangeLog
index e409478b..b3b1cd76 100644
--- a/php/ChangeLog
+++ b/php/ChangeLog
@@ -1,5 +1,10 @@
 msgpack extension changelog
 
+Version 0.5.1
+-------------
+	* Fixed include path for version check.
+	(Contributed by duedal)
+
 Version 0.5.0
 -------------
 	* Fix ZEND_DECLARE_MODULE_GLOBALS:
diff --git a/php/config.m4 b/php/config.m4
index 5bde72d6..a20de3e4 100644
--- a/php/config.m4
+++ b/php/config.m4
@@ -7,7 +7,7 @@ dnl without editing.
 dnl Check PHP version:
 
 AC_MSG_CHECKING(PHP version)
-AC_TRY_COMPILE([#include "php/main/php_version.h"], [
+AC_TRY_COMPILE([#include "$phpincludedir/main/php_version.h"], [
 #if PHP_MAJOR_VERSION < 5
 #error  this extension requires at least PHP version 5 or newer
 #endif
diff --git a/php/php_msgpack.h b/php/php_msgpack.h
index d677a1c7..bcd64996 100644
--- a/php/php_msgpack.h
+++ b/php/php_msgpack.h
@@ -2,7 +2,7 @@
 #ifndef PHP_MSGPACK_H
 #define PHP_MSGPACK_H
 
-#define MSGPACK_EXTENSION_VERSION "0.5.0"
+#define MSGPACK_EXTENSION_VERSION "0.5.1"
 
 #include "ext/standard/php_smart_str.h"