diff --git a/src/emu/device.h b/src/emu/device.h
index a1a4cafec77..ad22bd601e8 100644
--- a/src/emu/device.h
+++ b/src/emu/device.h
@@ -631,8 +631,8 @@ public:
 
 protected:
 	// internal state
-	shared_ptr_type *m_array[_Count];
-	astring m_tag[_Count];
+	shared_ptr_type *m_array[_Count+1];
+	astring m_tag[_Count+1];
 };
 
 // optional shared pointer array finder