diff --git a/.travis.yml b/.travis.yml
index 6df822de54..307664a91b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -61,8 +61,7 @@ after_success:
         echo "This is a PR. No coverage generated."
       fi
 
-after_script:
-  - |
+after_script: |
   if [ "${TRAVIS_EVENT_TYPE}" != "cron" ]; then
-    curl -X POST -H "Content-Type:application/json" -d "{\"attachments\": [{\"color\": \"danger\", \"fallback\": \"Build Failure: $TRAVIS_JOB_WEB_URL\", \"title\": \"Build Failure\", \"text\": \"$TRAVIS_JOB_WEB_URL\"}]}" $SLACK_URL
+    curl -X POST --data-urlencode 'payload={"attachments": [{"color": "danger", "fallback": "Build Failure: $TRAVIS_JOB_WEB_URL", "title": "Build Failure", "text": "$TRAVIS_JOB_WEB_URL"}]}' $SLACK_URL
   fi