diff --git a/plugins/common/functions b/plugins/common/functions
index 1bda3930e..8617e8c79 100755
--- a/plugins/common/functions
+++ b/plugins/common/functions
@@ -163,7 +163,7 @@ dokku_log_fail_quiet() {
 dokku_log_fail() {
   declare desc="log fail formatter"
   echo " !     $*" 1>&2
-  exit ${DOKKU_FAIL_EXIT_CODE:=1}
+  exit "${DOKKU_FAIL_EXIT_CODE:=1}"
 }
 
 dokku_log_stderr() {