diff --git a/Source/Plugins/3DFloorMode/ThreeDFloorMode.cs b/Source/Plugins/3DFloorMode/ThreeDFloorMode.cs
index efc11044..093ed5f2 100644
--- a/Source/Plugins/3DFloorMode/ThreeDFloorMode.cs
+++ b/Source/Plugins/3DFloorMode/ThreeDFloorMode.cs
@@ -51,6 +51,7 @@ namespace CodeImp.DoomBuilder.ThreeDFloorMode
 			  ButtonImage = "ThreeDFloorIcon.png",	// Image resource name for the button
 			  ButtonOrder = int.MinValue + 501,	// Position of the button (lower is more to the left)
 			  ButtonGroup = "000_editing",
+			  SupportedMapFormats = new[] { "HexenMapSetIO", "UniversalMapSetIO" },
 			  UseByDefault = true,
 			  SafeStartMode = false,
 			  Volatile = false)]
diff --git a/Source/Plugins/3DFloorMode/Windows/SlopeVertexEditForm.Designer.cs b/Source/Plugins/3DFloorMode/Windows/SlopeVertexEditForm.Designer.cs
index 4979ca50..915106f0 100644
--- a/Source/Plugins/3DFloorMode/Windows/SlopeVertexEditForm.Designer.cs
+++ b/Source/Plugins/3DFloorMode/Windows/SlopeVertexEditForm.Designer.cs
@@ -283,6 +283,7 @@
 			this.spline.TabIndex = 10;
 			this.spline.Text = "Spline";
 			this.spline.UseVisualStyleBackColor = true;
+			this.spline.Visible = false;
 			// 
 			// SlopeVertexEditForm
 			//