diff --git a/include/cbm510.h b/include/cbm510.h
index 7883e9cc6..7f692552f 100644
--- a/include/cbm510.h
+++ b/include/cbm510.h
@@ -100,7 +100,7 @@
 #define	SID	(*(struct __sid*)0xDA00)
 
 #include <_6526.h>
-#define CIA	(*(struct __cia*)0xDC00)
+#define CIA	(*(struct __6526*)0xDC00)
 
 #include <_6551.h>
 #define ACIA	(*(struct __6551*)0xDD00)
diff --git a/include/cbm610.h b/include/cbm610.h
index 88c5d3171..a83886114 100644
--- a/include/cbm610.h
+++ b/include/cbm610.h
@@ -85,7 +85,7 @@
 #define SID	(*(struct __sid*)0xDA00)
 
 #include <_6526.h>
-#define CIA     (*(struct __cia*)0xDC00)
+#define CIA     (*(struct __6526*)0xDC00)
 
 #include <_6551.h>
 #define ACIA    (*(struct __6551*)0xDD00)