diff -up mozilla-release/configure.in.old mozilla-release/configure.in
--- mozilla-release/configure.in.old	2015-04-28 20:31:45.000000000 +0200
+++ mozilla-release/configure.in	2015-04-28 20:32:40.807783614 +0200
@@ -3627,7 +3627,7 @@ MOZ_ARG_WITH_BOOL(system-nss,
     _USE_SYSTEM_NSS=1 )
 
 if test -n "$_USE_SYSTEM_NSS"; then
-    AM_PATH_NSS(3.18.1, [MOZ_NATIVE_NSS=1], [AC_MSG_ERROR([you don't have NSS installed or your version is too old])])
+    AM_PATH_NSS(3.18.0, [MOZ_NATIVE_NSS=1], [AC_MSG_ERROR([you don't have NSS installed or your version is too old])])
 fi
 
 if test -n "$MOZ_NATIVE_NSS"; then