diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h
index f6d20f6cca12..7a4db5fefd15 100644
--- a/arch/x86/include/asm/xen/hypercall.h
+++ b/arch/x86/include/asm/xen/hypercall.h
@@ -50,6 +50,8 @@
 #include <xen/interface/platform.h>
 #include <xen/interface/xen-mca.h>
 
+struct xen_dm_op_buf;
+
 /*
  * The hypercall asms have to meet several constraints:
  * - Work on 32- and 64-bit.
@@ -474,7 +476,7 @@ HYPERVISOR_xenpmu_op(unsigned int op, void *arg)
 
 static inline int
 HYPERVISOR_dm_op(
-	domid_t dom, unsigned int nr_bufs, void *bufs)
+	domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs)
 {
 	return _hypercall3(int, dm_op, dom, nr_bufs, bufs);
 }
diff --git a/include/xen/arm/hypercall.h b/include/xen/arm/hypercall.h
index 73db4b2eeb89..b40485e54d80 100644
--- a/include/xen/arm/hypercall.h
+++ b/include/xen/arm/hypercall.h
@@ -39,6 +39,8 @@
 #include <xen/interface/sched.h>
 #include <xen/interface/platform.h>
 
+struct xen_dm_op_buf;
+
 long privcmd_call(unsigned call, unsigned long a1,
 		unsigned long a2, unsigned long a3,
 		unsigned long a4, unsigned long a5);
@@ -53,7 +55,8 @@ int HYPERVISOR_physdev_op(int cmd, void *arg);
 int HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args);
 int HYPERVISOR_tmem_op(void *arg);
 int HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type);
-int HYPERVISOR_dm_op(domid_t domid, unsigned int nr_bufs, void *bufs);
+int HYPERVISOR_dm_op(domid_t domid, unsigned int nr_bufs,
+		     struct xen_dm_op_buf *bufs);
 int HYPERVISOR_platform_op_raw(void *arg);
 static inline int HYPERVISOR_platform_op(struct xen_platform_op *op)
 {