diff --git a/src/platforms/posix/socket.cpp b/src/platforms/posix/socket.cpp
index 8d4f8fbc..51cc5cc1 100644
--- a/src/platforms/posix/socket.cpp
+++ b/src/platforms/posix/socket.cpp
@@ -19,6 +19,7 @@
 
 #include "socket.hpp"
 
+#include <unistd.h>
 #include <sys/socket.h>
 #include <arpa/inet.h>
 #include <sys/types.h>