diff --git a/addons/imgui-godot/ImGuiGodot/ImGuiGD.cs b/addons/imgui-godot/ImGuiGodot/ImGuiGD.cs
index 1c74ae7..39ddf0d 100644
--- a/addons/imgui-godot/ImGuiGodot/ImGuiGD.cs
+++ b/addons/imgui-godot/ImGuiGodot/ImGuiGD.cs
@@ -36,6 +36,9 @@ public static float Scale
         get => _scale;
         set
         {
+            if (_inProcessFrame)
+                throw new InvalidOperationException("scale cannot be changed during process frame");
+
             if (_scale != value && value >= 0.25f)
             {
                 _scale = value;
@@ -45,6 +48,8 @@ public static float Scale
     }
     private static float _scale = 1.0f;
 
+    private static bool _inProcessFrame = false;
+
     public static IntPtr BindTexture(Texture2D tex)
     {
         return (IntPtr)tex.GetRid().Id;
@@ -117,6 +122,9 @@ public static void AddFontDefault()
 
     public static void RebuildFontAtlas()
     {
+        if (_inProcessFrame)
+            throw new InvalidOperationException("fonts cannot be changed during process frame");
+
         Internal.State.Instance.Fonts.RebuildFontAtlas(ScaleToDpi ? Scale * DpiFactor : Scale);
     }
 
@@ -128,6 +136,7 @@ public static void Update(double delta, Vector2 displaySize)
 
         Internal.State.Instance.Input.Update(io);
 
+        _inProcessFrame = true;
         ImGui.NewFrame();
     }
 
@@ -137,6 +146,7 @@ public static void Render()
 
         ImGui.UpdatePlatformWindows();
         Internal.State.Instance.Renderer.RenderDrawData();
+        _inProcessFrame = false;
     }
 
     public static void Shutdown()
diff --git a/src/MySecondNode.cs b/src/MySecondNode.cs
index a62b1c9..492a0b0 100644
--- a/src/MySecondNode.cs
+++ b/src/MySecondNode.cs
@@ -133,7 +133,7 @@ private void OnImGuiLayout()
             if (ImGui.RadioButton($"{s:0.00}", _scale == s))
             {
                 _scale = s;
-                CallDeferred("OnScaleChanged");
+                CallDeferred(nameof(OnScaleChanged));
             }
 
             if (i < 5) ImGui.SameLine();