diff --git a/Kernel/UnixTypes.h b/Kernel/UnixTypes.h
index bb77f506c6c..8bbf92dadb1 100644
--- a/Kernel/UnixTypes.h
+++ b/Kernel/UnixTypes.h
@@ -400,6 +400,7 @@ struct pollfd {
 #define SO_KEEPALIVE 3
 #define SO_ERROR 4
 #define SO_PEERCRED 5
+#define SO_REUSEADDR 6
 
 #define IPPROTO_IP 0
 #define IPPROTO_ICMP 1
diff --git a/Libraries/LibC/sys/socket.h b/Libraries/LibC/sys/socket.h
index 9c9dced6560..2207b8c7876 100644
--- a/Libraries/LibC/sys/socket.h
+++ b/Libraries/LibC/sys/socket.h
@@ -79,6 +79,7 @@ struct ucred {
 #define SO_KEEPALIVE 3
 #define SO_ERROR 4
 #define SO_PEERCRED 5
+#define SO_REUSEADDR 6
 
 int socket(int domain, int type, int protocol);
 int bind(int sockfd, const struct sockaddr* addr, socklen_t);