diff --git a/include/minix/com.h b/include/minix/com.h
index d1c1ee3fc..e1b4513db 100644
--- a/include/minix/com.h
+++ b/include/minix/com.h
@@ -702,8 +702,6 @@
 #define VM_MAP_PHYS		(VM_RQ_BASE+15)
 
 #define VM_UNMAP_PHYS		(VM_RQ_BASE+16)
-#	define VMUP_EP			m1_i1
-#	define VMUP_VADDR		m1_p1
 
 /* To VM: map in cache block by FS */
 #define VM_MAPCACHEPAGE		(VM_RQ_BASE+26)
diff --git a/include/minix/ipc.h b/include/minix/ipc.h
index 15bc6203a..6b2e52905 100644
--- a/include/minix/ipc.h
+++ b/include/minix/ipc.h
@@ -1856,6 +1856,13 @@ typedef struct {
 } mess_lsys_vm_map_phys;
 _ASSERT_MSG_SIZE(mess_lsys_vm_map_phys);
 
+typedef struct {
+	endpoint_t	ep;
+	void		*vaddr;
+	uint8_t		padding[48];
+} mess_lsys_vm_unmap_phys;
+_ASSERT_MSG_SIZE(mess_lsys_vm_unmap_phys);
+
 typedef struct {
 	endpoint_t m_source;		/* who sent the message */
 	int m_type;			/* what kind of message is it */
@@ -2093,6 +2100,7 @@ typedef struct {
 		mess_lc_ipc_semop	m_lc_ipc_semop;
 		mess_lc_vm_brk		m_lc_vm_brk;
 		mess_lsys_vm_map_phys	m_lsys_vm_map_phys;
+		mess_lsys_vm_unmap_phys	m_lsys_vm_unmap_phys;
 
 		mess_vfs_lchardriver_cancel	m_vfs_lchardriver_cancel;
 		mess_vfs_lchardriver_openclose	m_vfs_lchardriver_openclose;
diff --git a/lib/libsys/vm_map_phys.c b/lib/libsys/vm_map_phys.c
index bd1e183e1..1635c0e6e 100644
--- a/lib/libsys/vm_map_phys.c
+++ b/lib/libsys/vm_map_phys.c
@@ -29,8 +29,8 @@ vm_unmap_phys(endpoint_t who, void *vaddr, size_t len)
 	message m;
 
 	memset(&m, 0, sizeof(m));
-	m.VMUP_EP = who;
-	m.VMUP_VADDR = vaddr;
+	m.m_lsys_vm_unmap_phys.ep = who;
+	m.m_lsys_vm_unmap_phys.vaddr = vaddr;
 
 	return _taskcall(VM_PROC_NR, VM_UNMAP_PHYS, &m);
 }
diff --git a/servers/vm/mmap.c b/servers/vm/mmap.c
index dcdbf44b2..d6cc1cda8 100644
--- a/servers/vm/mmap.c
+++ b/servers/vm/mmap.c
@@ -496,7 +496,7 @@ int do_munmap(message *m)
 	endpoint_t target = SELF;
 
 	if(m->m_type == VM_UNMAP_PHYS) {
-		target = m->VMUP_EP;
+		target = m->m_lsys_vm_unmap_phys.ep;
 	} else if(m->m_type == VM_SHM_UNMAP) {
 		target = m->m_lc_vm_shm_unmap.forwhom;
 	}
@@ -511,7 +511,7 @@ int do_munmap(message *m)
         vmp = &vmproc[n];
 
 	if(m->m_type == VM_UNMAP_PHYS) {
-		addr = (vir_bytes) m->VMUP_VADDR;
+		addr = (vir_bytes) m->m_lsys_vm_unmap_phys.vaddr;
 	} else if(m->m_type == VM_SHM_UNMAP) {
 		addr = (vir_bytes) m->m_lc_vm_shm_unmap.addr;
 	} else	addr = (vir_bytes) m->VMUM_ADDR;