diff --git a/scanner/skillhub_scanner_app.py b/scanner/skillhub_scanner_app.py
index c008d17e2..9d6ad01a3 100644
--- a/scanner/skillhub_scanner_app.py
+++ b/scanner/skillhub_scanner_app.py
@@ -5,7 +5,9 @@ import inspect
 import logging
 import os
 import shutil
+import sys
 import tempfile
+from decimal import Decimal, InvalidOperation
 from functools import wraps
 from importlib import import_module
 from pathlib import Path
@@ -17,6 +19,25 @@ _RUNTIME_TEMP_ROOT = Path(
 )
 
 
+def _parse_upload_size_bytes(value: str) -> int:
+    """Accept exact integral scientific notation emitted by Helm for byte limits."""
+    try:
+        return max(1, int(value))
+    except ValueError:
+        if "e" not in value.lower():
+            raise
+
+    try:
+        amount = Decimal(value)
+    except InvalidOperation as exc:
+        raise ValueError("Scanner upload size must be an integer") from exc
+    if not amount.is_finite() or amount != amount.to_integral_value() or amount > sys.maxsize:
+        raise ValueError("Scanner upload size must be a finite supported integer")
+    if amount <= 1:
+        return 1
+    return int(amount)
+
+
 def _prepare_runtime_temp_root() -> None:
     """Recreate the scanner-owned temp root before upstream allocates request directories."""
     if _RUNTIME_TEMP_ROOT.name != "skillhub-scanner-runtime" or _RUNTIME_TEMP_ROOT.is_symlink():
@@ -41,8 +62,8 @@ from skill_scanner.cli import cli as _upstream_cli
 _upstream_router = import_module("skill_scanner.api.router")
 _MAX_CONCURRENT_SCANS = max(1, int(os.getenv("SKILLHUB_SCANNER_MAX_CONCURRENT_SCANS", "1")))
 _HARD_TIMEOUT_SECONDS = max(1, int(os.getenv("SKILLHUB_SCANNER_HARD_TIMEOUT_SECONDS", "930")))
-_upstream_router.MAX_UPLOAD_SIZE_BYTES = max(
-    1, int(os.getenv("SKILLHUB_SCANNER_MAX_UPLOAD_SIZE_BYTES", "110100480"))
+_upstream_router.MAX_UPLOAD_SIZE_BYTES = _parse_upload_size_bytes(
+    os.getenv("SKILLHUB_SCANNER_MAX_UPLOAD_SIZE_BYTES", "110100480")
 )
 _active_scans = 0
 _active_scans_guard = asyncio.Lock()
diff --git a/scanner/tests/test_skillhub_scanner_app.py b/scanner/tests/test_skillhub_scanner_app.py
index 2c3417065..580cc278d 100644
--- a/scanner/tests/test_skillhub_scanner_app.py
+++ b/scanner/tests/test_skillhub_scanner_app.py
@@ -236,6 +236,17 @@ class SkillHubScannerAppTest(unittest.IsolatedAsyncioTestCase):
 
         self.assertEqual(123456, module._router_stub.MAX_UPLOAD_SIZE_BYTES)
 
+    async def test_upload_limit_accepts_integral_scientific_notation(self):
+        module = _load_module({"SKILLHUB_SCANNER_MAX_UPLOAD_SIZE_BYTES": "1.1010048e+08"})
+        self.addCleanup(shutil.rmtree, module._test_temp_parent)
+
+        self.assertEqual(110100480, module._router_stub.MAX_UPLOAD_SIZE_BYTES)
+
+    async def test_upload_limit_rejects_invalid_scientific_notation(self):
+        for value in ("1.5e+0", "1e-1", "1e+", "1e999999", "NaN", "Infinity"):
+            with self.subTest(value=value), self.assertRaises(ValueError):
+                self.module._parse_upload_size_bytes(value)
+
     async def test_upload_limit_is_at_least_one_byte(self):
         module = _load_module({"SKILLHUB_SCANNER_MAX_UPLOAD_SIZE_BYTES": "0"})
         self.addCleanup(shutil.rmtree, module._test_temp_parent)