diff --git a/types/helmet/helmet-tests.ts b/types/helmet/helmet-tests.ts
index 53fba8e948..afedea6c23 100644
--- a/types/helmet/helmet-tests.ts
+++ b/types/helmet/helmet-tests.ts
@@ -58,6 +58,7 @@ function contentSecurityPolicyTest() {
         directives: {
             defaultSrc: ["'self'"]
         },
+        loose: false,
         setAllHeaders: true
     }));
 }
diff --git a/types/helmet/index.d.ts b/types/helmet/index.d.ts
index 1abe99c20f..6f89728e8a 100644
--- a/types/helmet/index.d.ts
+++ b/types/helmet/index.d.ts
@@ -60,6 +60,7 @@ declare namespace helmet {
         disableAndroid?: boolean;
         browserSniff?: boolean;
         directives?: IHelmetContentSecurityPolicyDirectives;
+        loose?: boolean;
     }
 
     export interface IHelmetDnsPrefetchControlConfiguration {