diff --git a/src/network/network_data.cpp b/src/network/network_data.cpp
index c56c7905f0..4bfc12ec81 100644
--- a/src/network/network_data.cpp
+++ b/src/network/network_data.cpp
@@ -34,7 +34,7 @@ void NetworkAddCommandQueue(NetworkClientSocket *cs, CommandPacket *cp)
 // Prepare a DoCommand to be send over the network
 void NetworkSend_Command(TileIndex tile, uint32 p1, uint32 p2, uint32 cmd, CommandCallback *callback, const char *text)
 {
-	assert((cmd & CMD_FLAG_MASK) == 0);
+	assert((cmd & CMD_FLAGS_MASK) == 0);
 
 	CommandPacket c;