diff --git a/src/node_os.cc b/src/node_os.cc
index 0b46af95f4ba78..9e5530646a3708 100644
--- a/src/node_os.cc
+++ b/src/node_os.cc
@@ -163,7 +163,7 @@ static void GetCPUInfo(const FunctionCallbackInfo<Value>& args) {
   // The array is in the format
   // [model, speed, (5 entries of cpu_times), model2, speed2, ...]
   std::vector<Local<Value>> result(count * 7);
-  for (size_t i = 0; i < count; i++) {
+  for (int i = 0; i < count; i++) {
     uv_cpu_info_t* ci = cpu_infos + i;
     result[i * 7] = OneByteString(isolate, ci->model);
     result[i * 7 + 1] = Number::New(isolate, ci->speed);