diff --git a/app/src/components/compose/CanvasToolbar.tsx b/app/src/components/compose/CanvasToolbar.tsx
index 53a9684..03f24b6 100644
--- a/app/src/components/compose/CanvasToolbar.tsx
+++ b/app/src/components/compose/CanvasToolbar.tsx
@@ -50,7 +50,10 @@ export function CanvasToolbar({
     if (!selectedFigure) return;
     const newDepth =
       direction === 'up' ? selectedFigure.z_depth + 1 : Math.max(0, selectedFigure.z_depth - 1);
-    updateFigure.mutate({ id: selectedFigure.id, data: { z_depth: newDepth } });
+    updateFigure.mutate(
+      { id: selectedFigure.id, data: { z_depth: newDepth } },
+      { onError: (err) => toast.error(err.message) },
+    );
   }
 
   function downloadPanel(file: PanelFile, panelCount: number, dpi: number) {
diff --git a/app/src/components/compose/CompositionCanvas.tsx b/app/src/components/compose/CompositionCanvas.tsx
index 9724e16..8807c22 100644
--- a/app/src/components/compose/CompositionCanvas.tsx
+++ b/app/src/components/compose/CompositionCanvas.tsx
@@ -104,14 +104,20 @@ export function CompositionCanvas({ projectId, figures, surface }: CompositionCa
 
   const handleDragEnd = useCallback(
     (figureId: string, normX: number, normY: number) => {
-      updateFigure.mutate({ id: figureId, data: { position_x: normX, position_y: normY } });
+      updateFigure.mutate(
+        { id: figureId, data: { position_x: normX, position_y: normY } },
+        { onError: (err) => toast.error(err.message) },
+      );
     },
     [updateFigure],
   );
 
   const handleScaleChange = useCallback(
     (figureId: string, scale: number) => {
-      updateFigure.mutate({ id: figureId, data: { scale } });
+      updateFigure.mutate(
+        { id: figureId, data: { scale } },
+        { onError: (err) => toast.error(err.message) },
+      );
     },
     [updateFigure],
   );