diff --git a/mod_entropy.c b/mod_entropy.c
index 448ea8c..7ceef76 100644
--- a/mod_entropy.c
+++ b/mod_entropy.c
@@ -35,6 +35,7 @@
 #include "http_config.h"
 #include "http_core.h"
 #include "http_log.h"
+#include "ap_release.h"
 #include "apu.h"
 #include "apr_general.h"
 #include "apr_sha1.h"
@@ -98,7 +99,7 @@ entropy_filter_in(
 	/**
 	 * add client ip to sha1
 	 */
-#if 4 > HTTP_VERSION_MINOR(number)
+#if 4 > AP_SERVER_MINORVERSION_NUMBER
 	remote_ip = connection->remote_ip;
 #else
 	remote_ip = connection->client_ip;