diff --git a/Dockerfile b/Dockerfile
index 274227b..b7723a6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -38,6 +38,6 @@ RUN apt-get update \
     && apt-get autoremove -y \
     && rm -rf /var/cache/*
 
-RUN echo "Snikket $BUILD_SERIES.$BUILD_ID" > /usr/lib/prosody/prosody.version
+RUN echo "Snikket $BUILD_SERIES $BUILD_ID" > /usr/lib/prosody/prosody.version
 
 VOLUME ["/snikket"]
diff --git a/snikket-modules/mod_update_check/mod_update_check.lua b/snikket-modules/mod_update_check/mod_update_check.lua
index 5ddb598..5fbd471 100644
--- a/snikket-modules/mod_update_check/mod_update_check.lua
+++ b/snikket-modules/mod_update_check/mod_update_check.lua
@@ -12,10 +12,11 @@ local check_interval = module:get_option_number("update_check_interval", 86400);
 local version_info = {};
 
 do
-	local version = prosody.version;
-	local branch, bugfix = version:match("(%S+)%.(%d+)$");
-	if branch then
-		version_info.branch, version_info.level = branch, bugfix;
+	local version_string = prosody.version;
+	-- "dev 128-00000", "release v2021.05r2"
+	local series, version = version_string:match("(%w+) (%S+)$");
+	if series then
+		version_info.branch, version_info.level = series, version;
 	end
 end