Index: abi/include/abi/cap.h
===================================================================
--- abi/include/abi/cap.h	(revision a35b458e9db1ca95e679799dc7c1b12c83359ca3)
+++ abi/include/abi/cap.h	(revision cbb37b60574b56acd864c01b9afca6a0ce28867f)
@@ -38,5 +38,12 @@
 #define CAP_NIL		0
 
-typedef int cap_handle_t;
+#define CAP_HANDLE_VALID(handle)	((handle) != CAP_NIL)
+#define CAP_HANDLE_RAW(handle)		((intptr_t) (handle))
+
+typedef void *cap_handle_t;
+
+typedef struct {} *cap_call_handle_t;
+typedef struct {} *cap_phone_handle_t;
+typedef struct {} *cap_irq_handle_t;
 
 #endif
Index: abi/include/abi/ipc/methods.h
===================================================================
--- abi/include/abi/ipc/methods.h	(revision a35b458e9db1ca95e679799dc7c1b12c83359ca3)
+++ abi/include/abi/ipc/methods.h	(revision cbb37b60574b56acd864c01b9afca6a0ce28867f)
@@ -39,5 +39,5 @@
 
 /* Well known phone descriptors */
-#define PHONE_NS  (CAP_NIL + 1)
+#define PHONE_NS  ((cap_phone_handle_t) (CAP_NIL + 1))
 
 /** Kernel IPC interfaces
Index: abi/include/abi/mm/as.h
===================================================================
--- abi/include/abi/mm/as.h	(revision a35b458e9db1ca95e679799dc7c1b12c83359ca3)
+++ abi/include/abi/mm/as.h	(revision cbb37b60574b56acd864c01b9afca6a0ce28867f)
@@ -36,4 +36,6 @@
 #define ABI_AS_H_
 
+#include <abi/cap.h>
+
 /** Address space area flags. */
 #define AS_AREA_READ         0x01
@@ -62,5 +64,5 @@
 
 typedef struct {
-	int pager;
+	cap_phone_handle_t pager;
 	sysarg_t id1;
 	sysarg_t id2;