diff -up comm-esr31/mozilla/configure.in.nss-3.18 comm-esr31/mozilla/configure.in
--- comm-esr31/mozilla/configure.in.nss-3.18	2015-07-15 12:11:13.745268957 +0200
+++ comm-esr31/mozilla/configure.in	2015-07-15 12:11:32.630243688 +0200
@@ -3655,7 +3655,7 @@ MOZ_ARG_WITH_BOOL(system-nss,
     _USE_SYSTEM_NSS=1 )
 
 if test -n "$_USE_SYSTEM_NSS"; then
-    AM_PATH_NSS(3.19.2, [MOZ_NATIVE_NSS=1], [AC_MSG_ERROR([you don't have NSS installed or your version is too old])])
+    AM_PATH_NSS(3.19.1, [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