diff --git a/lib/utils.js b/lib/utils.js
index b0aa896..56174c3 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -42,24 +42,25 @@ const scopesByFenceName = {
   'yml': 'source.yaml'
 };
 
-module.exports = {
-  scopeForFenceName (fenceName) {
+
+export function scopeForFenceName (fenceName: string): string {
     fenceName = fenceName.toLowerCase();
     let result = `source.${fenceName}`;
     if (scopesByFenceName[fenceName] != null) {
       result = scopesByFenceName[fenceName]
     }
     return result;
-  },
-  fenceNameForScope (scope) {
+}
+
+export function fenceNameForScope (scope: string): string {
     scope = scope.toLowerCase();
     let result = Object.keys(scopesByFenceName).filter(s => s == scope);
+    let resultOut: string
     if (result.length) {
-      result = result[0];
+      resultOut = result[0];
     }
     else {
-      result = scope.substr(scope.lastIndexOf('.') + 1);
+      resultOut = scope.substr(scope.lastIndexOf('.') + 1);
     }
-    return result;
-  }
-};
+    return resultOut;
+}