diff --git a/src/base.ts b/src/base.ts
index c59a90a38..bf12a0085 100644
--- a/src/base.ts
+++ b/src/base.ts
@@ -119,7 +119,7 @@ export abstract class AutoMapperBase {
       sourceMemberNamingConvention,
       destinationMemberNamingConvention,
     } = mapping;
-    const configKeys: Array<string> = [];
+    const configKeys = [];
 
     let destinationObj = new destination();