diff --git a/api/index.php b/api/index.php
index 1c32c4d0..d211942f 100644
--- a/api/index.php
+++ b/api/index.php
@@ -532,13 +532,14 @@ function routeFiles(
 
     if ($method === 'DELETE') {
         $file = implode('/', array_slice($parts, 1));
-        if (!$store->exists($file)) {
-            Response::error("{$noun} not found", 404);
-        }
+        // Asked before whether there is one: somebody else's folder tells a stranger nothing.
         $folder = HashedFileStore::folderOf($file);
         if (!$isAdmin && ($folder === '' || $folder !== $users->folderOf($user))) {
             Response::error('Only its owner may delete this file', 403);
         }
+        if (!$store->exists($file)) {
+            Response::error("{$noun} not found", 404);
+        }
         $uses = (new FileUsage(dirname(__DIR__) . '/data'))->of($file);
         if ($uses !== []) {
             Response::error(FileUsage::refusal($uses, $user, $isAdmin), 409);
diff --git a/src/editor/graph/AnnotationView.ts b/src/editor/graph/AnnotationView.ts
index ec4388d7..acface5b 100644
--- a/src/editor/graph/AnnotationView.ts
+++ b/src/editor/graph/AnnotationView.ts
@@ -18,6 +18,8 @@ const PAD = 8;
 export class AnnotationView extends Widget {
   private readonly box = new Graphics();
   private readonly caption: Text;
+  /** Colour and width of the caption's style, see `redraw`. */
+  private styleKey = '';
   selected = false;
 
   constructor(
@@ -105,7 +107,13 @@ export class AnnotationView extends Widget {
       .lineTo(this.w - 2, this.h - RESIZE_HANDLE / 2)
       .stroke({ width: 1, color: text, alpha: 0.5 });
 
-    this.caption.style = this.captionStyle(text);
+    // A new style draws the caption again even when nothing changed, and the graph redraws on every
+    // edit of the project, a stroke on a tilemap included (#347). So only a new colour or width sets one.
+    const styleKey = `${text}|${this.w}`;
+    if (styleKey !== this.styleKey) {
+      this.styleKey = styleKey;
+      this.caption.style = this.captionStyle(text);
+    }
     this.caption.text =
       this.kind === 'group'
         ? truncate(this.annotation.text, this.caption.style, Math.max(this.w - PAD * 2, 1))
diff --git a/tests/editor/annotation-view.test.ts b/tests/editor/annotation-view.test.ts
new file mode 100644
index 00000000..e749e330
--- /dev/null
+++ b/tests/editor/annotation-view.test.ts
@@ -0,0 +1,35 @@
+/**
+ * A graph draws its groups and comments again on every edit of the project, a stroke on a tilemap
+ * included. A caption that is given a new style is drawn again as text, so it keeps its style for as
+ * long as colour and width stay the same (#347).
+ */
+import type { Text } from 'pixi.js';
+import { describe, expect, it } from 'vitest';
+import { AnnotationView } from '../../src/editor/graph/AnnotationView';
+
+const note = { id: 'n1', x: 0, y: 0, w: 200, h: 120, text: 'Comment' };
+const captionOf = (view: AnnotationView) => view.children[1] as Text;
+
+describe('the caption of a group or comment', () => {
+  // A comment only: a group's title is cut to its width by measuring it, which needs a canvas. The
+  // groups are seen in the browser, in e2e 40c-iii.
+  it('keeps its style through a redraw that changes nothing', () => {
+    const view = new AnnotationView({ ...note }, 'note');
+    const style = captionOf(view).style;
+    view.redraw();
+    view.sync({ ...note });
+    expect(captionOf(view).style).toBe(style);
+  });
+
+  it('is given a new style for a new width or colour', () => {
+    const view = new AnnotationView({ ...note }, 'note');
+    const style = captionOf(view).style;
+    view.sync({ ...note, w: 260 });
+    const wider = captionOf(view).style;
+    expect(wider).not.toBe(style);
+    expect(wider.wordWrapWidth).toBe(260 - 16);
+    view.sync({ ...note, w: 260, color: 0xffffff });
+    expect(captionOf(view).style).not.toBe(wider);
+    expect(captionOf(view).style.fill).not.toBe(wider.fill);
+  });
+});