diff --git a/src/playsim/p_mobj.cpp b/src/playsim/p_mobj.cpp
index df6661871..e863445f2 100644
--- a/src/playsim/p_mobj.cpp
+++ b/src/playsim/p_mobj.cpp
@@ -401,7 +401,8 @@ void AActor::Serialize(FSerializer &arc)
 		("unmorphtime", UnmorphTime)
 		("morphflags", MorphFlags)
 		("premorphproperties", PremorphProperties)
-		("morphexitflash", MorphExitFlash);
+		("morphexitflash", MorphExitFlash)
+		("damagesource", damagesource);
 
 
 		SerializeTerrain(arc, "floorterrain", floorterrain, &def->floorterrain);