diff --git a/test/share-socket.ts b/test/share-socket.ts
index 72b46709..43877d7a 100644
--- a/test/share-socket.ts
+++ b/test/share-socket.ts
@@ -439,7 +439,7 @@ describe('share-socket', function () {
         const req = request(`coap://localhost:${port + 1}`)
         req.end()
 
-        function fastForward (increase: number, max: number): void {
+        function fastForward (increase, max): void {
             clock.tick(increase)
             if (increase < max) {
                 fastForward(increase, max - increase)