diff --git a/newgrf_config.c b/newgrf_config.c
--- a/newgrf_config.c
+++ b/newgrf_config.c
@@ -328,6 +328,8 @@ const GRFConfig *FindGRFConfig(uint32 gr
 	return NULL;
 }
 
+#ifdef ENABLE_NETWORK
+
 /** Structure for UnknownGRFs; this is a lightweight variant of GRFConfig */
 typedef struct UnknownGRF UnknownGRF;
 struct UnknownGRF {
@@ -377,6 +379,8 @@ char *FindUnknownGRFName(uint32 grfid, u
 	return grf->name;
 }
 
+#endif /* ENABLE_NETWORK */
+
 
 /* Retrieve a NewGRF from the current config by its grfid */
 GRFConfig *GetGRFConfig(uint32 grfid)
diff --git a/newgrf_config.h b/newgrf_config.h
--- a/newgrf_config.h
+++ b/newgrf_config.h
@@ -55,8 +55,10 @@ char *GRFBuildParamList(char *dst, const
 /* In newgrf_gui.c */
 void ShowNewGRFSettings(bool editable, bool show_params, bool exec_changes, GRFConfig **config);
 
+#ifdef ENABLE_NETWORK
 /* For communication about GRFs over the network */
 #define UNKNOWN_GRF_NAME_PLACEHOLDER "<Unknown>"
 char *FindUnknownGRFName(uint32 grfid, uint8 *md5sum, bool create);
+#endif /* ENABLE_NETWORK */
 
 #endif /* NEWGRF_CONFIG_H */
diff --git a/players.c b/players.c
--- a/players.c
+++ b/players.c
@@ -844,7 +844,10 @@ int32 CmdPlayerCtrl(TileIndex tile, uint
 		if (!_networking) return CMD_ERROR;
 
 		/* Has the network client a correct ClientID? */
-		if (!(flags & DC_EXEC) || cid >= MAX_CLIENT_INFO) return 0;
+		if (!(flags & DC_EXEC)) return 0;
+#ifdef ENABLE_NETWORK
+		if (cid >= MAX_CLIENT_INFO) return 0;
+#endif /* ENABLE_NETWORK */
 
 		/* Delete multiplayer progress bar */
 		DeleteWindowById(WC_NETWORK_STATUS_WINDOW, 0);