diff --git a/tac/tacchaind.Dockerfile b/tac/tacchaind.Dockerfile
index c26c7352..b1f53470 100644
--- a/tac/tacchaind.Dockerfile
+++ b/tac/tacchaind.Dockerfile
@@ -1,6 +1,6 @@
-# tacchaind — binary download from GitHub releases (v1.6.0).
+# tacchaind — binary download from GitHub releases (v1.6.4).
 # Downloads pre-built linux-amd64 binary and verifies against checksums.txt.
-ARG VERSION=v1.6.0
+ARG VERSION=v1.6.4
 
 FROM alpine:3.21