diff --git a/apps/web/src/components/DiagramEditorPane.test.mjs b/apps/web/src/components/DiagramEditorPane.test.mjs
index a5f4d6ac..9963c4cd 100644
--- a/apps/web/src/components/DiagramEditorPane.test.mjs
+++ b/apps/web/src/components/DiagramEditorPane.test.mjs
@@ -275,12 +275,19 @@ describe("diagram editor canvas surface", () => {
   test("reuses the architecture shape-library trigger across every diagram kind", () => {
     expect(toolbarSource).toContain("export const DiagramToolbarAddTrigger");
     expect(toolbarSource).toContain("<DropdownMenuTrigger asChild>");
-    expect(toolbarSource).toContain('<Button size="sm" variant="soft" onPointerEnter={onPointerEnter}>');
+    expect(toolbarSource).toContain('if (event.pointerType === "mouse") onPointerEnter(event);');
     expect(toolbarSource).toContain('<Boxes className="h-4 w-4" />');
     expect(toolbarSource).toContain('{t("diagram.componentLibrary")}');
     expect(source.match(/<DiagramToolbarAddTrigger onPointerEnter=/g)).toHaveLength(2);
   });
 
+  test("keeps a shape menu opened by hover from blocking the rest of the editor", () => {
+    // Touch fires pointerenter right before the pointerdown that toggles the
+    // menu, and a modal menu hides the back button while it is open.
+    expect(toolbarSource).not.toContain("onPointerEnter={onPointerEnter}");
+    expect(source.match(/<DropdownMenu modal=\{false\} open=\{open\}/g)).toHaveLength(2);
+  });
+
   test("exposes connection handles on flowcharts and architecture components with safe connection rules", () => {
     expect(source).toContain("const hasPorts = isConnectableDiagram(kind) && node.shape !== \"boundary\"");
     expect(source).toContain("const FLOW_PORT_HIT_RADIUS = 14");
diff --git a/apps/web/src/components/DiagramEditorPane.tsx b/apps/web/src/components/DiagramEditorPane.tsx
index 4b4c6246..4c98012a 100644
--- a/apps/web/src/components/DiagramEditorPane.tsx
+++ b/apps/web/src/components/DiagramEditorPane.tsx
@@ -686,7 +686,7 @@ const DiagramInsertMenu = ({
 }) => {
   const [open, setOpen] = useState(false);
   return (
-    <DropdownMenu open={open} onOpenChange={setOpen}>
+    <DropdownMenu modal={false} open={open} onOpenChange={setOpen}>
       <DiagramToolbarAddTrigger onPointerEnter={() => setOpen(true)} />
       <DropdownMenuContent align="start">
         {items.map((item) => {
diff --git a/apps/web/src/components/DiagramToolbar.tsx b/apps/web/src/components/DiagramToolbar.tsx
index ba4477ea..1c813122 100644
--- a/apps/web/src/components/DiagramToolbar.tsx
+++ b/apps/web/src/components/DiagramToolbar.tsx
@@ -174,7 +174,15 @@ export const DiagramToolbarAddTrigger = ({
   const { t } = useTranslation();
   return (
     <DropdownMenuTrigger asChild>
-      <Button size="sm" variant="soft" onPointerEnter={onPointerEnter}>
+      <Button
+        size="sm"
+        variant="soft"
+        // Hover opening is for mice. A touch fires pointerenter right before the
+        // pointerdown that toggles the menu, which would close it again.
+        onPointerEnter={(event) => {
+          if (event.pointerType === "mouse") onPointerEnter(event);
+        }}
+      >
         <Boxes className="h-4 w-4" />
         {t("diagram.componentLibrary")}
         <ChevronDown className="h-3.5 w-3.5 text-slate-400" />