diff --git a/stepmania/src/Song.cpp b/stepmania/src/Song.cpp
index 74b3512dbf..886e8eb6b5 100644
--- a/stepmania/src/Song.cpp
+++ b/stepmania/src/Song.cpp
@@ -1077,6 +1077,8 @@ void Song::AddSteps( Steps* pSteps )
 
 void Song::DeleteSteps( const Steps* pSteps, bool bReAutoGen )
 {
+	ASSERT( !pSteps->IsAutogen() );
+
 	// Avoid any stale Note::parent pointers by removing all AutoGen'd Steps,
 	// then adding them again.