diff --git a/docker-compose.yml b/docker-compose.yml
index b7d2767b84..47182b9c75 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -113,7 +113,7 @@ services:
       - SSM_ENV_SITE_NAME=development
 
   mockpass:
-    build: https://github.com/opengovsg/mockpass.git
+    build: https://github.com/opengovsg/mockpass.git#v3.1.3
     depends_on:
       - backend
     environment: