diff --git a/BizHawk.Client.Common/movie/MovieRecord.cs b/BizHawk.Client.Common/movie/MovieRecord.cs
index a285fef9a7..267e92dad2 100644
--- a/BizHawk.Client.Common/movie/MovieRecord.cs
+++ b/BizHawk.Client.Common/movie/MovieRecord.cs
@@ -9,7 +9,7 @@ namespace BizHawk.Client.Common
 {
 	public class MovieRecord
 	{
-		private readonly byte[] _state;
+		private byte[] _state = new byte[0];
 		private Dictionary<string, bool> _boolButtons = new Dictionary<string, bool>();
 
 		public MovieRecord(Dictionary<string, bool> buttons, bool captureState)
@@ -55,6 +55,11 @@ namespace BizHawk.Client.Common
 			_boolButtons.Clear();
 		}
 
+		public void ClearState()
+		{
+			_state = new byte[0];
+		}
+
 		public bool HasState
 		{
 			get { return State.Any(); }
diff --git a/BizHawk.Client.Common/movie/MovieRecordList.cs b/BizHawk.Client.Common/movie/MovieRecordList.cs
index 34e7a74420..af78bb9166 100644
--- a/BizHawk.Client.Common/movie/MovieRecordList.cs
+++ b/BizHawk.Client.Common/movie/MovieRecordList.cs
@@ -41,5 +41,13 @@ namespace BizHawk.Client.Common
 				RemoveRange(index, Count - index);
 			}
 		}
+
+		public void TruncateStates(int index)
+		{
+			for (int i = index; i < Count; i++)
+			{
+				this[i].ClearState();
+			}
+		}
 	}
 }
diff --git a/BizHawk.Client.Common/movie/TasMovie.cs b/BizHawk.Client.Common/movie/TasMovie.cs
index 7d3db941ec..8995663f26 100644
--- a/BizHawk.Client.Common/movie/TasMovie.cs
+++ b/BizHawk.Client.Common/movie/TasMovie.cs
@@ -35,6 +35,7 @@ namespace BizHawk.Client.Common
 		public void ToggleButton(int frame, string buttonName)
 		{
 			_records[frame].Buttons[buttonName] ^= true;
+			Changes = true;
 		}
 
 		public void SetButton(int frame, string buttonName, bool value)