--- a/configure
+++ b/configure
@@ -290,7 +290,7 @@ if test $compat -eq 0; then
   VER2=$(sed -n -e '/ZLIBNG_VERSION "/s/.*"\([0-9]*\.[0-9]*\)\..*/\1/p' < ${SRCDIR}/zlib-ng.h.in)
   VER1=$(sed -n -e '/ZLIBNG_VERSION "/s/.*"\([0-9]*\)\..*/\1/p' < ${SRCDIR}/zlib-ng.h.in)
 else
-  VER=$(sed -n -e '/ZLIB_VERSION "/s/.*"\(.*\)".*/\1/p' < ${SRCDIR}/zlib.h.in)
+  VER=$(sed -n -e '/ZLIB_VERSION "/s/.*"\(.*\).zlib-ng".*/\1/p' < ${SRCDIR}/zlib.h.in)
   VER3=$(sed -n -e '/ZLIB_VERSION "/s/.*"\([0-9]*\.[0-9]*\.[0-9]*\).*/\1/p' < ${SRCDIR}/zlib.h.in)
   VER2=$(sed -n -e '/ZLIB_VERSION "/s/.*"\([0-9]*\.[0-9]*\)\..*/\1/p' < ${SRCDIR}/zlib.h.in)
   VER1=$(sed -n -e '/ZLIB_VERSION "/s/.*"\([0-9]*\)\..*/\1/p' < ${SRCDIR}/zlib.h.in)