diff --git a/.ci/docker-compose.yml b/.ci/docker-compose.yml
index 779eb133..b85937e4 100644
--- a/.ci/docker-compose.yml
+++ b/.ci/docker-compose.yml
@@ -16,7 +16,7 @@ services:
 
   httpbin:
     container_name: ci_httpbin
-    image: ghcr.io/mccutchen/go-httpbin:2.20
+    image: ghcr.io/mccutchen/go-httpbin:2.21
     ports:
       - "127.0.0.1:8081:8081"
     command: ["go-httpbin", "-port", "8081"]
diff --git a/.devcontainer/docker-compose.yml b/.devcontainer/docker-compose.yml
index 4c4cba10..bfc1aacb 100644
--- a/.devcontainer/docker-compose.yml
+++ b/.devcontainer/docker-compose.yml
@@ -26,7 +26,7 @@ services:
 
   httpbin:
     container_name: gotify-httpbin
-    image: ghcr.io/mccutchen/go-httpbin:2.20
+    image: ghcr.io/mccutchen/go-httpbin:2.21
     ports:
       - "8081:8081"
     command: ["go-httpbin", "-port", "8081"]