diff --git a/frontend/src/business/components/api/test/components/assertion/ApiAssertionText.vue b/frontend/src/business/components/api/test/components/assertion/ApiAssertionText.vue
index c199b1a2ad..804b4b413c 100644
--- a/frontend/src/business/components/api/test/components/assertion/ApiAssertionText.vue
+++ b/frontend/src/business/components/api/test/components/assertion/ApiAssertionText.vue
@@ -62,7 +62,7 @@
             description += " contains: " + this.value;
             break;
           case "NOT_CONTAINS":
-            expression = "^((?!" + this.value + ").)*$";
+            expression = "(?s)^((?!" + this.value + ").)*$";
             description += " not contains: " + this.value;
             break;
           case "EQUALS":