diff --git a/bellows/ezsp/__init__.py b/bellows/ezsp/__init__.py
index 32761829..9c9e8064 100644
--- a/bellows/ezsp/__init__.py
+++ b/bellows/ezsp/__init__.py
@@ -397,7 +397,7 @@ async def _get_mfg_custom_eui_64(self) -> t.EmberEUI64 | None:
 
         # Manufacturing tokens do not exist in RCP firmware: all reads are empty
         if not data:
-            raise EzspError("Firmware does not support MFG_CUSTOM_EUI_64 token")
+            raise ValueError("Firmware does not support MFG_CUSTOM_EUI_64 token")
 
         mfg_custom_eui64, _ = t.EmberEUI64.deserialize(data)
 
@@ -410,7 +410,7 @@ async def can_burn_userdata_custom_eui64(self) -> bool:
         """Checks if the device EUI64 can be burned into USERDATA."""
         try:
             return await self._get_mfg_custom_eui_64() is None
-        except EzspError:
+        except ValueError:
             return False
 
     async def can_rewrite_custom_eui64(self) -> bool:
@@ -442,7 +442,11 @@ async def write_custom_eui64(
 
         # A custom EUI64 can be stored in NV3 storage (rewritable)
         nv3_eui64_key = await self._get_nv3_restored_eui64_key()
-        mfg_custom_eui64 = await self._get_mfg_custom_eui_64()
+
+        try:
+            mfg_custom_eui64 = await self._get_mfg_custom_eui_64()
+        except ValueError:
+            mfg_custom_eui64 = None
 
         if nv3_eui64_key is not None:
             # Prefer NV3 storage over MFG_CUSTOM_EUI_64, as it can be rewritten
diff --git a/tests/test_ezsp.py b/tests/test_ezsp.py
index c2a59388..d9238ccb 100644
--- a/tests/test_ezsp.py
+++ b/tests/test_ezsp.py
@@ -644,6 +644,32 @@ async def test_write_custom_eui64(ezsp_f):
     ezsp_f.setTokenData.assert_not_called()
 
 
+async def test_write_custom_eui64_rcp(ezsp_f):
+    """Test writing a custom EUI64 with RPC firmware."""
+
+    old_eui64 = t.EmberEUI64.convert("AA" * 8)
+    new_eui64 = t.EmberEUI64.convert("BB" * 8)
+
+    ezsp_f.getEui64 = AsyncMock(return_value=[old_eui64])
+    ezsp_f.setMfgToken = AsyncMock(return_value=[t.EmberStatus.INVALID_CALL])
+    ezsp_f.setTokenData = AsyncMock(return_value=[t.EmberStatus.SUCCESS])
+
+    # RCP firmware does not support manufacturing tokens
+    ezsp_f.getMfgToken = AsyncMock(return_value=[b""])
+    ezsp_f.getTokenData = AsyncMock(return_value=[t.EmberStatus.SUCCESS, b"\xFF" * 8])
+
+    await ezsp_f.write_custom_eui64(new_eui64)
+
+    ezsp_f.setMfgToken.assert_not_called()
+    ezsp_f.setTokenData.mock_calls == [
+        call(
+            t.NV3KeyId.NVM3KEY_STACK_RESTORED_EUI64,
+            0,
+            new_eui64.serialize(),
+        )
+    ]
+
+
 @patch.object(ezsp.EZSP, "version", new_callable=AsyncMock)
 @patch.object(ezsp.EZSP, "reset", new_callable=AsyncMock)
 @patch("bellows.uart.connect", return_value=MagicMock(spec_set=uart.Gateway))