diff -up memcached-1.0.2/config.m4.orig memcached-1.0.2/config.m4
--- memcached-1.0.2/config.m4.orig	2011-09-17 17:23:48.000000000 +0200
+++ memcached-1.0.2/config.m4	2011-09-17 17:24:52.000000000 +0200
@@ -94,7 +94,7 @@ if test "$PHP_MEMCACHED" != "no"; then
       igbinary_inc_path="$abs_srcdir/include/php"
     elif test -f "$abs_srcdir/ext/igbinary/igbinary.h"; then
       igbinary_inc_path="$abs_srcdir"
-    elif test -f "$phpincludedir/ext/session/igbinary.h"; then
+    elif test -f "$phpincludedir/ext/igbinary/igbinary.h"; then
       igbinary_inc_path="$phpincludedir"
     else
       for i in php php4 php5 php6; do