diff --git a/scripts/generate_pack.py b/scripts/generate_pack.py
index f4a47410..00ccf0d9 100644
--- a/scripts/generate_pack.py
+++ b/scripts/generate_pack.py
@@ -2432,6 +2432,11 @@ def _run_verify_packs(args):
             with zipfile.ZipFile(zip_path) as zf:
                 zf.extractall(extract_dir)
 
+            # Auto-detect flat vs nested extraction
+            is_flat = bool(base_dest) and not os.path.isdir(
+                os.path.join(extract_dir, base_dest)
+            )
+
             missing = []
             hash_fail = []
             ok = 0
@@ -2442,7 +2447,7 @@ def _run_verify_packs(args):
                         continue
                     fp = (
                         os.path.join(extract_dir, base_dest, dest)
-                        if base_dest
+                        if base_dest and not is_flat
                         else os.path.join(extract_dir, dest)
                     )
                     # Case-insensitive fallback
diff --git a/tests/test_e2e.py b/tests/test_e2e.py
index bf797df0..e6b6604c 100644
--- a/tests/test_e2e.py
+++ b/tests/test_e2e.py
@@ -3383,10 +3383,17 @@ class TestE2E(unittest.TestCase):
             registry_path,
             emulators_dir=self.emulators_dir,
         )
+        # Detect flat vs nested ZIP to build expected paths
         base = manifest.get("base_destination", "")
+        is_flat = bool(base) and not any(
+            n.startswith(base + "/") for n in zip_names
+        )
         manifest_dests = set()
         for f in manifest["files"]:
-            d = f"{base}/{f['dest']}" if base else f["dest"]
+            if base and not is_flat:
+                d = f"{base}/{f['dest']}"
+            else:
+                d = f["dest"]
             manifest_dests.add(d)
 
         self.assertEqual(manifest_dests, zip_names)