diff --git a/routstr/balance.py b/routstr/balance.py
index 184c445a..83bda1c9 100644
--- a/routstr/balance.py
+++ b/routstr/balance.py
@@ -23,6 +23,7 @@ from .lightning import lightning_router
 from .wallet import (
     classify_redemption_error,
     credit_balance,
+    is_mint_connection_error,
     recieve_token,
     send_to_lnurl,
     send_token,
@@ -435,14 +436,10 @@ async def refund_wallet_endpoint(
                 "has_refund_address": bool(key.refund_address),
             },
         )
-        if (
-            "mint" in error_msg.lower()
-            or "connection" in error_msg.lower()
-            or "ConnectError" in str(type(e))
-        ):
-            raise HTTPException(status_code=503, detail=f"Mint service unavailable: {error_msg}")
+        if is_mint_connection_error(e):
+            raise HTTPException(status_code=503, detail="Mint service unavailable")
         else:
-            raise HTTPException(status_code=500, detail=f"Refund failed: {error_msg}")
+            raise HTTPException(status_code=500, detail="Refund failed")
 
     await _refund_cache_set(bearer_value, result)
 
diff --git a/tests/integration/test_wallet_refund.py b/tests/integration/test_wallet_refund.py
index 1c62385d..1cbd6b4b 100644
--- a/tests/integration/test_wallet_refund.py
+++ b/tests/integration/test_wallet_refund.py
@@ -14,6 +14,7 @@ from httpx import AsyncClient
 from sqlmodel import select
 
 from routstr.core.db import ApiKey, CashuTransaction
+from routstr.wallet import MintConnectionError
 
 
 @pytest.mark.integration
@@ -503,26 +504,19 @@ async def test_mint_unavailability_handling(
 
     # The global mock in conftest.py is already in place,
     # so we need to temporarily modify it
-    from unittest.mock import patch
+    raw_error = "Mint unavailable: Connection refused"
 
-    # Make the send_token method raise an exception
+    # Make the send_token method raise a typed mint connection exception.
     with patch(
         "routstr.balance.send_token",
-        side_effect=Exception("Mint unavailable: Connection refused"),
+        side_effect=MintConnectionError(raw_error),
     ):
-        # The exception should propagate as a 503 error (Service Unavailable)
-        # But we need to handle it properly
-        try:
-            response = await authenticated_client.post("/v1/wallet/refund")
-            # If we get here, check the status code
-            assert response.status_code == 503
-            assert "Mint service unavailable" in response.json()["detail"]
-        except Exception as e:
-            # If the exception propagates, that's also a failure scenario
-            assert "Mint unavailable" in str(e)
+        response = await authenticated_client.post("/v1/wallet/refund")
+        assert response.status_code == 503
+        assert response.json()["detail"] == "Mint service unavailable"
+        assert raw_error not in response.text
 
         # Balance should remain unchanged (transaction should roll back)
-        # Note: Current implementation might not handle this perfectly
         wallet_response = await authenticated_client.get("/v1/wallet/")
         assert wallet_response.status_code == 200
         assert wallet_response.json()["balance"] == 10_000_000
diff --git a/tests/unit/test_balance.py b/tests/unit/test_balance.py
index e5ac57c4..31ceb339 100644
--- a/tests/unit/test_balance.py
+++ b/tests/unit/test_balance.py
@@ -340,7 +340,10 @@ async def test_apikey_refund_restores_balance_on_mint_failure() -> None:
 
     with (
         patch("routstr.balance.get_billing_key", AsyncMock(return_value=key)),
-        patch("routstr.balance.send_token", AsyncMock(side_effect=Exception("mint down"))),
+        patch(
+            "routstr.balance.send_token",
+            AsyncMock(side_effect=MintConnectionError("raw mint outage detail")),
+        ),
         patch("routstr.balance.store_cashu_transaction", AsyncMock()),
         patch("routstr.balance._refund_cache_get", AsyncMock(return_value=None)),
         patch("routstr.balance._refund_cache_set", AsyncMock()),
@@ -354,10 +357,46 @@ async def test_apikey_refund_restores_balance_on_mint_failure() -> None:
             )
 
     assert exc_info.value.status_code == 503
+    assert exc_info.value.detail == "Mint service unavailable"
+    assert "raw mint outage detail" not in exc_info.value.detail
     # Verify two exec calls: debit + restore
     assert session.exec.await_count == 2
 
 
+@pytest.mark.asyncio
+async def test_apikey_refund_generic_failure_is_sanitized_500() -> None:
+    """Unexpected send-side failures restore balance without leaking exception text."""
+    from fastapi import HTTPException
+
+    key = _make_api_key(balance=5000, refund_currency="sat")
+    raw_error = "database secret token raw-mint-response"
+
+    session = MagicMock()
+    session.get = AsyncMock(return_value=key)
+    session.exec = AsyncMock(side_effect=[_update_result(1), _update_result(1)])
+    session.commit = AsyncMock()
+
+    with (
+        patch("routstr.balance.get_billing_key", AsyncMock(return_value=key)),
+        patch("routstr.balance.send_token", AsyncMock(side_effect=RuntimeError(raw_error))),
+        patch("routstr.balance.store_cashu_transaction", AsyncMock()),
+        patch("routstr.balance._refund_cache_get", AsyncMock(return_value=None)),
+        patch("routstr.balance._refund_cache_set", AsyncMock()),
+        patch("routstr.balance.logger"),
+    ):
+        with pytest.raises(HTTPException) as exc_info:
+            await refund_wallet_endpoint(
+                authorization="Bearer sk-testhash",
+                x_cashu=None,
+                session=session,
+            )
+
+    assert exc_info.value.status_code == 500
+    assert exc_info.value.detail == "Refund failed"
+    assert raw_error not in exc_info.value.detail
+    assert session.exec.await_count == 2
+
+
 # ---------------------------------------------------------------------------
 # no-create guarantee: fresh Cashu/unknown sk- tokens must not create API keys
 # ---------------------------------------------------------------------------