diff --git a/d3xp/Misc.cpp b/d3xp/Misc.cpp
index 415b188..4b67cd4 100644
--- a/d3xp/Misc.cpp
+++ b/d3xp/Misc.cpp
@@ -1882,7 +1882,9 @@ void idFuncShootProjectile::Event_Activate( idEntity *activator ) {
 idFuncShootProjectile::WriteToSnapshot
 ================
 */
-void idFuncShootProjectile::WriteToSnapshot( idBitMsg &msg ) const {
+void idFuncShootProjectile::WriteToSnapshot( idBitMsgDelta &msg ) const {
+	// DG: at least in vanilla Doom3 the argument should really be idBitMsgDelta, not idBitMsg!
+	// FIXME: now that the argument type is fixed, maybe the commented out code below can be uncommented again?
 	// 	msg.WriteBits( hidden ? 1 : 0, 1 );
 	// 	msg.WriteFloat( renderEntity.shaderParms[ SHADERPARM_PARTICLE_STOPTIME ] );
 	// 	msg.WriteFloat( renderEntity.shaderParms[ SHADERPARM_TIMEOFFSET ] );
@@ -1893,7 +1895,9 @@ void idFuncShootProjectile::WriteToSnapshot( idBitMsg &msg ) const {
 idFuncShootProjectile::ReadFromSnapshot
 ================
 */
-void idFuncShootProjectile::ReadFromSnapshot( const idBitMsg &msg ) {
+void idFuncShootProjectile::ReadFromSnapshot( const idBitMsgDelta &msg ) {
+	// DG: at least in vanilla Doom3 the argument should really be idBitMsgDelta, not idBitMsg!
+	// FIXME: now that the argument type is fixed, maybe the commented out code below can be uncommented again?
 	// 	hidden = msg.ReadBits( 1 ) != 0;
 	// 	renderEntity.shaderParms[ SHADERPARM_PARTICLE_STOPTIME ] = msg.ReadFloat();
 	// 	renderEntity.shaderParms[ SHADERPARM_TIMEOFFSET ] = msg.ReadFloat();
diff --git a/d3xp/Misc.h b/d3xp/Misc.h
index 1bd2d79..9c63c68 100644
--- a/d3xp/Misc.h
+++ b/d3xp/Misc.h
@@ -368,8 +368,9 @@ public:
 
 	virtual void				Think();
 
-	virtual void				WriteToSnapshot( idBitMsg &msg ) const;
-	virtual void				ReadFromSnapshot( const idBitMsg &msg );
+	// DG: at least in vanilla Doom3 the arguments should really be idBitMsgDelta, not idBitMsg!
+	virtual void				WriteToSnapshot( idBitMsgDelta &msg ) const;
+	virtual void				ReadFromSnapshot( const idBitMsgDelta &msg );
 
 private:
 	int							mRespawnDelay;