diff --git a/tools/cfn2ts/lib/codegen.ts b/tools/cfn2ts/lib/codegen.ts
index 56965ee5b2b43..37da0266521c5 100644
--- a/tools/cfn2ts/lib/codegen.ts
+++ b/tools/cfn2ts/lib/codegen.ts
@@ -173,7 +173,7 @@ export default class CodeGenerator {
     }
   }
 
-  private emitResourceType(resourceName: genspec.CodeName, spec: schema.ResourceType, deprecated?: genspec.CodeName) {
+  private emitResourceType(resourceName: genspec.CodeName, spec: schema.ResourceType, deprecated?: genspec.CodeName): void {
     this.beginNamespace(resourceName);
 
     //