diff --git a/nx/include/switch/svc.h b/nx/include/switch/svc.h
index 5c110975..87571c58 100644
--- a/nx/include/switch/svc.h
+++ b/nx/include/switch/svc.h
@@ -24,5 +24,6 @@ Result svcConnectToNamedPort(Handle* session, const char* name);
 Result svcBreak(u32 BreakReason, u64 inval1, u64 inval2);
 Result svcAcceptSession(Handle *session_handle, Handle port_handle);
 Result svcReplyAndReceive(s32* index, const Handle* handles, s32 handleCount, Handle replyTarget, u64 timeout);
+Result svcQueryIoMapping(u64* virtaddr, u64 physaddr, u64 size);
 Result svcManageNamedPort(Handle* portServer, const char* name, s32 maxSessions);
 
diff --git a/nx/source/svc.s b/nx/source/svc.s
index 784953bf..372723df 100644
--- a/nx/source/svc.s
+++ b/nx/source/svc.s
@@ -53,6 +53,14 @@ SVC_BEGIN svcReplyAndReceive
 	ret
 SVC_END
 
+SVC_BEGIN svcQueryIoMapping
+	str x0, [sp, #-16]!
+	svc 0x55
+	ldr x2, [sp], #16
+	str x1, [x2]
+	ret
+SVC_END
+
 SVC_BEGIN svcManageNamedPort
 	str x0, [sp, #-16]!
 	svc 0x71