diff --git a/src/runtime/rand_test.go b/src/runtime/rand_test.go
index f8831b05f9f..1b84c79d24f 100644
--- a/src/runtime/rand_test.go
+++ b/src/runtime/rand_test.go
@@ -25,7 +25,7 @@ func BenchmarkFastrandHashiter(b *testing.B) {
 	}
 	b.RunParallel(func(pb *testing.PB) {
 		for pb.Next() {
-			for _ = range m {
+			for range m {
 				break
 			}
 		}
diff --git a/src/runtime/string_test.go b/src/runtime/string_test.go
index 7633cfde046..c6e925d2e07 100644
--- a/src/runtime/string_test.go
+++ b/src/runtime/string_test.go
@@ -125,7 +125,7 @@ func BenchmarkRuneIterate(b *testing.B) {
 		for _, sd := range stringdata {
 			b.Run(sd.name, func(b *testing.B) {
 				for i := 0; i < b.N; i++ {
-					for _ = range sd.data {
+					for range sd.data {
 					}
 				}
 			})
@@ -135,7 +135,7 @@ func BenchmarkRuneIterate(b *testing.B) {
 		for _, sd := range stringdata {
 			b.Run(sd.name, func(b *testing.B) {
 				for i := 0; i < b.N; i++ {
-					for _, _ = range sd.data {
+					for range sd.data {
 					}
 				}
 			})