* Author(s): cefn
 """
+import os
 
 try:
     import threading
             self._i2c = _I2C(frequency=frequency)
             return
         if detector.board.microchip_mcp2221:
-            from adafruit_blinka.microcontroller.mcp2221.i2c import I2C as _I2C
-
+            if (
+                "BLINKA_FORCECHIP" in os.environ
+                and os.environ["BLINKA_FORCEBOARD"] == "MICROCHIP_MCP2221"
+            ):
+                from adafruit_blinka.microcontroller.fake_mcp2221.i2c import I2C as _I2C
+            else:
+                from adafruit_blinka.microcontroller.mcp2221.i2c import I2C as _I2C
             self._i2c = _I2C(frequency=frequency)
             return
         if detector.board.greatfet_one: