diff --git a/Source/Core/Controls/SidedefPartLightControl.cs b/Source/Core/Controls/SidedefPartLightControl.cs
index 44d40e37..5e6c53b1 100644
--- a/Source/Core/Controls/SidedefPartLightControl.cs
+++ b/Source/Core/Controls/SidedefPartLightControl.cs
@@ -165,7 +165,7 @@ namespace CodeImp.DoomBuilder.Controls
 			if (preventchanges)
 				return;
 
-			((LinedefEditFormUDMF)ParentForm).MakeUndo();
+			((LinedefEditFormSRB2)ParentForm).MakeUndo();
 
 			// Reset the increment step for +++/---
 			light.ResetIncrementStep();
@@ -208,7 +208,7 @@ namespace CodeImp.DoomBuilder.Controls
 			reset.Visible = (cbAbsolute.CheckState != CheckState.Unchecked || light.Text != "0");
 			General.Map.IsChanged = true;
 
-			((LinedefEditFormUDMF)ParentForm).ValuesChangedExternal();
+			((LinedefEditFormSRB2)ParentForm).ValuesChangedExternal();
 		}
 
 		private void cbAbsolute_CheckedChanged(object sender, EventArgs e)
@@ -216,7 +216,7 @@ namespace CodeImp.DoomBuilder.Controls
 			if (preventchanges)
 				return;
 
-			((LinedefEditFormUDMF)ParentForm).MakeUndo();
+			((LinedefEditFormSRB2)ParentForm).MakeUndo();
 
 			if (cbAbsolute.Checked)
 			{
@@ -242,7 +242,7 @@ namespace CodeImp.DoomBuilder.Controls
 						sd.Fields.Remove(fieldabsolutename);
 			}
 
-			((LinedefEditFormUDMF)ParentForm).ValuesChangedExternal();
+			((LinedefEditFormSRB2)ParentForm).ValuesChangedExternal();
 		}
 
 		#endregion
diff --git a/Source/Core/Windows/LinedefEditFormSRB2.cs b/Source/Core/Windows/LinedefEditFormSRB2.cs
index 22b025e7..1604a9ed 100644
--- a/Source/Core/Windows/LinedefEditFormSRB2.cs
+++ b/Source/Core/Windows/LinedefEditFormSRB2.cs
@@ -626,6 +626,14 @@ namespace CodeImp.DoomBuilder.Windows
 			}
 		}
 
+		/// <summary>
+		/// Runs the OnValuesChanged event. Use after updating properties from other controls.
+		/// </summary>
+		public void ValuesChangedExternal()
+		{
+			OnValuesChanged?.Invoke(this, EventArgs.Empty);
+		}
+
 		#endregion
 
 		#region ================== Events