--- Socket.cc
+++ Socket.cc
@@ -212,7 +212,7 @@
 int Socket::read(char *data, int size) {
   if (pending) {
     int opt = 0;
-    size_t osz = sizeof(int);
+    socklen_t osz = sizeof(int);
     getsockopt(fd, SOL_SOCKET, SO_ERROR, &opt, &osz);
     pending = 0;
     if (opt != 0)