diff --git a/web/app.rb b/web/app.rb
index 7b38e7e..44e4307 100644
--- a/web/app.rb
+++ b/web/app.rb
@@ -48,7 +48,7 @@ MAX_JSON_BODY_BYTES = begin
     DEFAULT_MAX_JSON_BODY_BYTES
   end
 # Fallback version string used when Git metadata is unavailable.
-VERSION_FALLBACK = "v0.3.0"
+VERSION_FALLBACK = "v0.4.0"
 DEFAULT_REFRESH_INTERVAL_SECONDS = 60
 REFRESH_INTERVAL_SECONDS = begin
     raw = ENV.fetch("REFRESH_INTERVAL_SECONDS", DEFAULT_REFRESH_INTERVAL_SECONDS.to_s)