diff --git a/server/util_test.go b/server/util_test.go
index 6cfa6f5855a..f68de7595ff 100644
--- a/server/util_test.go
+++ b/server/util_test.go
@@ -24,7 +24,7 @@ func BenchmarkParseSize(b *testing.B) {
 	}
 }
 
-func deferUnlock(mu sync.Mutex) {
+func deferUnlock(mu *sync.Mutex) {
 	mu.Lock()
 	defer mu.Unlock()
 }
@@ -33,11 +33,11 @@ func BenchmarkDeferMutex(b *testing.B) {
 	var mu sync.Mutex
 	b.SetBytes(1)
 	for i := 0; i < b.N; i++ {
-		deferUnlock(mu)
+		deferUnlock(&mu)
 	}
 }
 
-func noDeferUnlock(mu sync.Mutex) {
+func noDeferUnlock(mu *sync.Mutex) {
 	mu.Lock()
 	mu.Unlock()
 }
@@ -46,6 +46,6 @@ func BenchmarkNoDeferMutex(b *testing.B) {
 	var mu sync.Mutex
 	b.SetBytes(1)
 	for i := 0; i < b.N; i++ {
-		noDeferUnlock(mu)
+		noDeferUnlock(&mu)
 	}
 }