diff --git a/Userland/Libraries/LibCore/UDPServer.cpp b/Userland/Libraries/LibCore/UDPServer.cpp
index 6716865e6b..33d3609c70 100644
--- a/Userland/Libraries/LibCore/UDPServer.cpp
+++ b/Userland/Libraries/LibCore/UDPServer.cpp
@@ -33,6 +33,7 @@
 #include <unistd.h>
 
 #ifndef SOCK_NONBLOCK
+#    include <fcntl.h>
 #    include <sys/ioctl.h>
 #endif