diff --git a/src/devices/bus/coco/coco_gmc.cpp b/src/devices/bus/coco/coco_gmc.cpp
index 23731deaf73..73853eea654 100644
--- a/src/devices/bus/coco/coco_gmc.cpp
+++ b/src/devices/bus/coco/coco_gmc.cpp
@@ -32,7 +32,9 @@ MACHINE_CONFIG_END
 //  GLOBAL VARIABLES
 //**************************************************************************
 
-const device_type COCO_PAK_GMC = device_creator<coco_pak_gmc_device>;
+//const device_type COCO_PAK_GMC = device_creator<coco_pak_gmc_device>;
+
+DEFINE_DEVICE_TYPE(COCO_PAK_GMC, coco_pak_gmc_device, "cocopakgmc", "CoCo Games Master Cartridge")
 
 //-------------------------------------------------
 //  coco_pak_device - constructor
diff --git a/src/devices/bus/coco/coco_gmc.h b/src/devices/bus/coco/coco_gmc.h
index ceb0652f490..70f0f882969 100644
--- a/src/devices/bus/coco/coco_gmc.h
+++ b/src/devices/bus/coco/coco_gmc.h
@@ -27,5 +27,7 @@ private:
 
 
 // device type definition
-extern const device_type COCO_PAK_GMC;
+//extern const device_type COCO_PAK_GMC;
+DECLARE_DEVICE_TYPE(COCO_PAK_GMC, coco_pak_gmc_device)
+
 #endif  /* __COCO_GMC_H__ */