diff --git a/integration/cloudbuild/testbase/Dockerfile b/integration/cloudbuild/testbase/Dockerfile
index dd766d18da..4fe38767e5 100644
--- a/integration/cloudbuild/testbase/Dockerfile
+++ b/integration/cloudbuild/testbase/Dockerfile
@@ -1,5 +1,5 @@
 # This Dockerfile builds a base image for Trillan integration tests.
-FROM golang:1.21.5-bookworm@sha256:2d3b13c2a6368032e9697e64e7c923184e6e3be03cf01eadff27de124114e64e
+FROM golang:1.21.6-bookworm@sha256:688ad7f282ce711cc28676531f45d5b840790e28a689fbd4e8e4ac181e23e9c4
 
 WORKDIR /testbase