diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5cc5f8ea7..a08760ea8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 - Silenced a false-positive `MaxListenersExceededWarning` logged on every request proxied through an external rewrite. [#1697](https://github.com/sourcebot-dev/sourcebot/pull/1697)
 - Upgraded `next` to `^16.3.8`. [#1709](https://github.com/sourcebot-dev/sourcebot/pull/1709)
+- Fixed implicit directories in the file tree carrying the leaf file's path, which broke folder expansion and the `/api/git/tree` payload. [#1712](https://github.com/sourcebot-dev/sourcebot/pull/1712)
 
 ## [5.1.15] - 2026-09-29
 
diff --git a/packages/web/src/features/git/utils.test.ts b/packages/web/src/features/git/utils.test.ts
index e4aa5f8e2..e52d93f3b 100644
--- a/packages/web/src/features/git/utils.test.ts
+++ b/packages/web/src/features/git/utils.test.ts
@@ -103,3 +103,20 @@ test('buildFileTree builds a sorted tree from a flat list', () => {
     });
 });
 
+test('buildFileTree gives implicit directories their own path, not the leaf file path', () => {
+    const flatList: { type: string, path: string }[] = [
+        { type: 'blob', path: 'src/components/buttons/PrimaryButton.tsx' },
+    ];
+
+    const tree = buildFileTree(flatList);
+
+    const src = tree.children[0];
+    const components = src.children[0];
+    const buttons = components.children[0];
+
+    expect(src.path).toBe('src');
+    expect(components.path).toBe('src/components');
+    expect(buttons.path).toBe('src/components/buttons');
+    expect(buttons.children[0].path).toBe('src/components/buttons/PrimaryButton.tsx');
+});
+
diff --git a/packages/web/src/features/git/utils.ts b/packages/web/src/features/git/utils.ts
index f9b1a71e7..4f12f1fb6 100644
--- a/packages/web/src/features/git/utils.ts
+++ b/packages/web/src/features/git/utils.ts
@@ -67,7 +67,11 @@ export const buildFileTree = (flatList: { type: string, path: string }[]): FileT
             if (!next) {
                 next = {
                     name: part,
-                    path: item.path,
+                    // A node's path is its own location, not the leaf's: an
+                    // implicit directory (`src` for `src/main.ts`) used to get
+                    // the file's path, which broke folder expansion, route
+                    // sync and the /api/git/tree payload.
+                    path: parts.slice(0, i + 1).join('/'),
                     type: nodeType,
                     children: [],
                 };