diff --git a/backend/app/services/gltf.py b/backend/app/services/gltf.py
index 999e381..d84c386 100644
--- a/backend/app/services/gltf.py
+++ b/backend/app/services/gltf.py
@@ -15,6 +15,7 @@ from typing import Any, Optional
 
 # GLB binary header magic bytes ("glTF").
 _GLB_MAGIC = b"glTF"
+_GLB_MAGIC_INT = 0x46546C67  # b"glTF" interpreted as little-endian uint32
 _GLB_JSON_CHUNK_TYPE = 0x4E4F534A  # "JSON"
 _GLB_BIN_CHUNK_TYPE = 0x004E4942  # "BIN\0"
 
@@ -48,7 +49,7 @@ def _parse_glb(content: bytes) -> dict[str, Any]:
         raise ValueError("GLB file is too short")
 
     magic, _version, _length = struct.unpack_from("<III", content, 0)
-    if magic != _GLB_MAGIC:
+    if magic != _GLB_MAGIC_INT:
         raise ValueError("invalid GLB magic")
 
     offset = 12
@@ -79,9 +80,6 @@ def _parse_glb(content: bytes) -> dict[str, Any]:
 def _parse_gltf_json(content: bytes) -> dict[str, Any]:
     """Parse a plain .gltf JSON file."""
     stripped = content.lstrip()
-    if not stripped.startswith(b"{"):
-        raise ValueError("glTF JSON does not start with an object")
-
     try:
         payload = json.loads(stripped.decode("utf-8"))
     except (ValueError, UnicodeDecodeError) as exc: