diff --git a/docker/docker-compose.1804.51.yaml b/docker/docker-compose.1804.51.yaml
index c10b821..f534f18 100644
--- a/docker/docker-compose.1804.51.yaml
+++ b/docker/docker-compose.1804.51.yaml
@@ -11,8 +11,8 @@ services:
 
   test:
     image: swift-metrics:18.04-5.1
-    environment: []
-      #- SANITIZER_ARG=--sanitize=thread
+    environment:
+      - SANITIZER_ARG=--sanitize=thread
 
   shell:
     image: swift-metrics:18.04-5.1