diff --git a/PamhagenSysCtrl/Helpers/Pipeline/Graph.cs b/PamhagenSysCtrl/Helpers/Pipeline/Graph.cs
index 136b275..bbade7f 100644
--- a/PamhagenSysCtrl/Helpers/Pipeline/Graph.cs
+++ b/PamhagenSysCtrl/Helpers/Pipeline/Graph.cs
@@ -163,6 +163,10 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
             Graph.SetPos(s, cx - w / 2, cy - h / 2, scale);
         }
 
+        public ISet<INode> GetHover(Point? p, double scale) {
+            return p is Point v ? GetHover(v.X, v.Y, scale) : new HashSet<INode>();
+        }
+
         public ISet<INode> GetHover(double x, double y, double scale) {
             return Nodes.Where(n => n.IsInside(x / scale, y / scale)).ToHashSet();
         }
diff --git a/PamhagenSysCtrl/Windows/PlantSchemeWindow.xaml.cs b/PamhagenSysCtrl/Windows/PlantSchemeWindow.xaml.cs
index e0371b7..8b63752 100644
--- a/PamhagenSysCtrl/Windows/PlantSchemeWindow.xaml.cs
+++ b/PamhagenSysCtrl/Windows/PlantSchemeWindow.xaml.cs
@@ -489,7 +489,8 @@ namespace PamhagenSysCtrl.Windows {
                 e.Pump.IsActive || Graph.GetFreePath([e.Source, e.Sink], overrideStart: true) == null);
         }
 
-        private ISet<INode> UpdateScheme(Point pos, bool down) {
+        private ISet<INode> UpdateScheme(Point? pos, bool down) {
+            if (!SchemeCanvas.IsMouseOver) pos = null;
             foreach (var e in Graph.Edges) {
                 e.Highlight = null;
                 e.Flow = null;
@@ -509,7 +510,7 @@ namespace PamhagenSysCtrl.Windows {
             SetFastSelectButton(FastSelectButton_MP2_Forward, App.Plant?.State.MP2_State == MotorState.Forward ? 1 : 0, !(App.Plant?.State.MP2_HasClearance ?? false));
             SetFastSelectButton(FastSelectButton_MP2_Stop, App.Plant?.State.MP2_State == MotorState.Halt ? 2 : 0);
 
-            _hover = Graph.GetHover(pos.X, pos.Y, RoundedScale);
+            _hover = Graph.GetHover(pos, RoundedScale);
             var hoverButtons = FastSelectPaths.Where(b => b.Key.IsMouseOver).ToDictionary();
             Path? hoverPathDeactivate = null;
             if (App.Plant?.ManualControlMode ?? false) {