diff --git a/.github/workflows/mirror.yaml b/.github/workflows/mirror.yaml
index 66cca348f..2d191edf5 100644
--- a/.github/workflows/mirror.yaml
+++ b/.github/workflows/mirror.yaml
@@ -17,6 +17,7 @@ on:
           - registry-1.docker.io/library/golang
           - registry-1.docker.io/library/postgres
           - registry-1.docker.io/dxflrs/garage
+          - registry-1.docker.io/fullstorydev/grpcurl
           - ghcr.io/astral-sh/uv
       image-index-manifest-tag:
         description: |
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9b717026d..00a589e44 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,7 @@ All notable changes to this project will be documented in this file.
 
 - opensearch-dashboards: Bump cdxgen to 13.0.1 and pin the CycloneDX spec version to 1.6 ([#1600]).
 - opa, statsd-exporter: Bump cyclonedx-gomod to 1.12.0 ([#1639]).
+- testing-tools: Pull `grpcurl` from our own mirror instead of directly from Docker Hub ([#1671]).
 
 ### Fixed
 
@@ -90,6 +91,7 @@ All notable changes to this project will be documented in this file.
 [#1662]: https://github.com/stackabletech/docker-images/pull/1662
 [#1664]: https://github.com/stackabletech/docker-images/pull/1664
 [#1670]: https://github.com/stackabletech/docker-images/pull/1670
+[#1671]: https://github.com/stackabletech/docker-images/pull/1671
 
 ## [26.7.0] - 2026-07-21
 
diff --git a/testing-tools/Dockerfile b/testing-tools/Dockerfile
index a86491102..9660149c8 100644
--- a/testing-tools/Dockerfile
+++ b/testing-tools/Dockerfile
@@ -2,7 +2,9 @@
 # check=error=true
 
 ARG GRPCURL_VERSION
-FROM fullstorydev/grpcurl:v${GRPCURL_VERSION} AS grpcurl
+# Mirrored from registry-1.docker.io/fullstorydev/grpcurl via .github/workflows/mirror.yaml.
+# For updated versions check https://github.com/fullstorydev/grpcurl/releases
+FROM oci.stackable.tech/sdp/fullstorydev/grpcurl:v${GRPCURL_VERSION} AS grpcurl
 
 # Find the latest version:
 #