diff --git a/test-driver b/test-driver
index 7d560a34c2098869d49b95d515d4915b580cd420..529b5f37e95548446cb0f6c692e2c4476dba4e13 100755
--- a/test-driver
+++ b/test-driver
@@ -113,6 +113,9 @@ case "$cmd" in
         ;;
 
     run)
+        # The 'yaml' output format has slightly more legible errors.
+        export ANSIBLE_STDOUT_CALLBACK=yaml
+
         for playbook in "${float_dir}/test/integration-test-docker.yml" "$@"; do
             log Running test playbook ${playbook}
             ${float_dir}/float run ${playbook} \