diff --git a/Makefile.version b/Makefile.version
index f2a8f1e..b5c1ec2 100644
--- a/Makefile.version
+++ b/Makefile.version
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: LGPL-3.0-or-later
-VERSION := 6.3a
+VERSION := 6.4
UNPACKED_VERSION := $(shell echo $(VERSION) | sed -e 's/\([0-9]\+\.[0-9]\+\)\(.*\)/\1/')
BUILDARG_VERSION := --build-arg VERSION=$(VERSION) --build-arg UNPACKED_VERSION=$(UNPACKED_VERSION)
IMAGENAME := docker.io/silviof/docker-languagetool