diff --git a/spanlogger/spanlogger_test.go b/spanlogger/spanlogger_test.go
index 5e281b3a9..fa22a15c8 100644
--- a/spanlogger/spanlogger_test.go
+++ b/spanlogger/spanlogger_test.go
@@ -258,7 +258,7 @@ func BenchmarkSpanLoggerAwareCaller(b *testing.B) {
 
 	}
 
-	defaultStackDepth := 5
+	const defaultStackDepth = 5
 
 	b.Run("with go-kit's Caller", func(b *testing.B) {
 		runBenchmark(b, log.Caller(defaultStackDepth))