diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go
index fac5ca49ce..6a2c85aa9f 100644
--- a/src/runtime/malloc.go
+++ b/src/runtime/malloc.go
@@ -292,6 +292,7 @@ func mallocinit() {
 		arenaSizes := []uintptr{
 			512 << 20,
 			256 << 20,
+			128 << 20,
 		}
 
 		for _, arenaSize := range arenaSizes {