diff --git a/dlls/ws2_32/socket.c b/dlls/ws2_32/socket.c
index 246a0e2819b..0ed1af3092a 100644
--- a/dlls/ws2_32/socket.c
+++ b/dlls/ws2_32/socket.c
@@ -826,6 +826,7 @@ static const int ws_aiflag_map[][2] =
 #ifdef  AI_V4MAPPED
     MAP_OPTION( AI_V4MAPPED ),
 #endif
+    MAP_OPTION( AI_ALL ),
     MAP_OPTION( AI_ADDRCONFIG ),
 };
 
diff --git a/include/ws2tcpip.h b/include/ws2tcpip.h
index 5a444dcb5f3..5ba891185b5 100644
--- a/include/ws2tcpip.h
+++ b/include/ws2tcpip.h
@@ -72,6 +72,7 @@ typedef ADDRINFOA ADDRINFO, *LPADDRINFO;
 # define AI_CANONNAME              0x00000002
 # define AI_NUMERICHOST            0x00000004
 # define AI_NUMERICSERV            0x00000008
+# define AI_ALL                    0x00000100
 # define AI_ADDRCONFIG             0x00000400
 # define AI_V4MAPPED               0x00000800
 # define AI_NON_AUTHORITATIVE      0x00004000
@@ -93,6 +94,7 @@ typedef ADDRINFOA ADDRINFO, *LPADDRINFO;
 # define WS_AI_CANONNAME              0x00000002
 # define WS_AI_NUMERICHOST            0x00000004
 # define WS_AI_NUMERICSERV            0x00000008
+# define WS_AI_ALL                    0x00000100
 # define WS_AI_ADDRCONFIG             0x00000400
 # define WS_AI_V4MAPPED               0x00000800
 # define WS_AI_NON_AUTHORITATIVE      0x00004000