diff --git a/sys/posix/include/sys/socket.h b/sys/posix/include/sys/socket.h
index 52fcd6d4bb68510f036178a216c496311cfa2335..ecadc5197ffe90375e46b3ca66728fc7b9cbb40d 100644
--- a/sys/posix/include/sys/socket.h
+++ b/sys/posix/include/sys/socket.h
@@ -94,7 +94,7 @@ extern "C" {
 #define SO_TYPE         (15)    /**< Socket type. */
 /** @} */
 
-typedef unsigned int sa_family_t;   /**< address family type */
+typedef unsigned short sa_family_t;   /**< address family type */
 
 /**
  * @brief   Used to define the socket address.