diff --git a/types/moment-duration-format/index.d.ts b/types/moment-duration-format/index.d.ts
index eb81f2551a..6c09e59e36 100644
--- a/types/moment-duration-format/index.d.ts
+++ b/types/moment-duration-format/index.d.ts
@@ -5,7 +5,16 @@
 
 
 declare namespace moment {
-    interface Duration {
-        format(template: string, precision?: string, settings?: any): string;
+    interface DurationFormatSettings {
+      template?: string;
+      precision?: number;
+      trim?: boolean|string;
+      forceLength?: boolean;
     }
-}
\ No newline at end of file
+
+    interface Duration {
+        format(template: string, precision?: number, settings?: DurationFormatSettings): string;
+        format(template: string, settings?: DurationFormatSettings): string;
+        format(settings: DurationFormatSettings): string;
+    }
+}