diff --git a/src/band/integrations/omp.py b/src/band/integrations/omp.py
index a4370d697..e65cc3bfc 100644
--- a/src/band/integrations/omp.py
+++ b/src/band/integrations/omp.py
@@ -291,7 +291,7 @@ def normalize_omp_mcp_device_call(
             return name, args
         try:
             parsed = json.loads(content)
-        except json.JSONDecodeError:
+        except ValueError:
             return canonical, args
         if not isinstance(parsed, dict):
             return canonical, args
diff --git a/tests/integrations/test_omp.py b/tests/integrations/test_omp.py
index 8667243fc..15e2c8924 100644
--- a/tests/integrations/test_omp.py
+++ b/tests/integrations/test_omp.py
@@ -2,6 +2,8 @@
 
 from __future__ import annotations
 
+import sys
+
 import pytest
 
 from band.integrations.omp import (
@@ -159,6 +161,25 @@ def test_a_malformed_write_to_a_band_tool_keeps_its_identity(content: str) -> No
     ) == ("band_send_message", arguments)
 
 
+def test_an_oversized_integer_payload_keeps_the_tool_identity() -> None:
+    """``json.loads`` refuses an integer past the interpreter's digit limit
+    with a bare ``ValueError``; that payload is malformed like any other."""
+    arguments = {
+        "path": "xd://mcp__band_send_message",
+        "content": '{"count":' + "9" * 5000 + "}",
+        "append": False,
+    }
+    limit = sys.get_int_max_str_digits()
+    sys.set_int_max_str_digits(4300)
+    try:
+        projected = normalize_omp_mcp_device_call(
+            "write", arguments, frozenset({"band_send_message"}), kind="execute"
+        )
+    finally:
+        sys.set_int_max_str_digits(limit)
+    assert projected == ("band_send_message", arguments)
+
+
 @pytest.mark.parametrize(
     "arguments",
     [