diff --git a/scripts/prepare_remote_fallbacks.py b/scripts/prepare_remote_fallbacks.py
index f71a151..33694e2 100644
--- a/scripts/prepare_remote_fallbacks.py
+++ b/scripts/prepare_remote_fallbacks.py
@@ -22,6 +22,7 @@ FALLBACKS = [
         "revision": "v1.3",
         "url": "https://github.com/Dusk-92/WowPresence/releases/download/v1.3/WowPresence.zip",
         "kind": "wowpresence_zip",
+        "size": 141423,
         "sha256": "9b2dca9c69b5ab3b6dae3ef3b3efc9671779a227802ebb6ac98cb22bc6ea448a",
     },
     {
@@ -30,6 +31,8 @@ FALLBACKS = [
         "revision": "c252bbdc2aef1ac928eb237cf4d28edc21806ed8",
         "url": "https://raw.githubusercontent.com/seacrabsam/patch-herb/c252bbdc2aef1ac928eb237cf4d28edc21806ed8/patch-H.mpq",
         "kind": "mpq",
+        "size": 575628,
+        "sha256": "45b6b6795465a93104de213e0a36e1290b005a852cd6d03a8d21103efaefa0a7",
     },
     {
         "id": "visual_darker_nights",
@@ -37,6 +40,8 @@ FALLBACKS = [
         "revision": "1",
         "url": "https://pub-0f05631d243e4046993fc02ca7be9542.r2.dev/patches/patch-N.mpq",
         "kind": "mpq",
+        "size": 201362,
+        "sha256": "31dcd9f779ef1f4e9c4e71b5da58948781989f72c0454fa59fdd173947d24084",
     },
     {
         "id": "visual_pretty_night_sky",
@@ -44,6 +49,8 @@ FALLBACKS = [
         "revision": "1",
         "url": "https://drive.usercontent.google.com/download?id=1qu99ZS-SQFfTtYodBmZWYiHmxL8QtUY4&export=download&confirm=t",
         "kind": "mpq",
+        "size": 1390151,
+        "sha256": "b72e5837139772dff5e436c6a6375910fcb5c34ae5742512968463425c4520dd",
     },
     {
         "id": "visual_epoch_water",
@@ -51,6 +58,8 @@ FALLBACKS = [
         "revision": "1",
         "url": "https://drive.usercontent.google.com/download?id=1xRx9OrznbgbE1uBae3H3OGke9UoXtzmU&export=download&confirm=t",
         "kind": "mpq",
+        "size": 20411526,
+        "sha256": "30a969c185cc082a0eb158a7901de889af815426c1e5baec373649688b3151aa",
     },
     {
         "id": "visual_fog_pushback",
@@ -58,6 +67,8 @@ FALLBACKS = [
         "revision": "1",
         "url": "https://drive.usercontent.google.com/download?id=14aHvyfr_ACL-UURbNa_fXRPcfQZoIw8n&export=download&confirm=t",
         "kind": "mpq",
+        "size": 51281,
+        "sha256": "c59b87f7e9425ee890e2b869ea0d26cde84a68e3ee1004e18bb6a29b294c3e0d",
     },
 ]
 
@@ -163,6 +174,12 @@ def main():
             )
 
         size = os.path.getsize(destination)
+        expected_size = item.get("size")
+        if expected_size is not None and size != expected_size:
+            raise RuntimeError(
+                f"Size mismatch for {item['id']}: expected {expected_size}, got {size}"
+            )
+
         manifest["fallbacks"][item["id"]] = {
             "filename": item["filename"],
             "kind": item["kind"],