diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index 2b9da7a54..85ca7662e 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -4398,9 +4398,11 @@ AActor *P_SpawnMapThing (FMapThing *mthing, int position)
 	// Check if this actor's mapthing has a conversation defined
 	if (mthing->Conversation > 0)
 	{
-		mobj->ConversationRoot = GetConversation(mthing->Conversation);
-		if (mobj->ConversationRoot != -1)
+		// Make sure that this does not partially overwrite the default dialogue settings.
+		int root = GetConversation(mthing->Conversation);
+		if (root != -1)
 		{
+			mobj->ConversationRoot = root;
 			mobj->Conversation = StrifeDialogues[mobj->ConversationRoot];
 		}
 	}
diff --git a/src/p_usdf.cpp b/src/p_usdf.cpp
index 7bcca2204..b831b4140 100644
--- a/src/p_usdf.cpp
+++ b/src/p_usdf.cpp
@@ -407,7 +407,7 @@ class USDFParser : public UDMFParserBase
 				}
 			}
 		}
-		if (type == NULL)
+		if (type == NULL && dlgid == 0)
 		{
 			sc.ScriptMessage("No valid actor type defined in conversation.");
 			return false;