diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c
index 2124624b781743..ff0ad8006ec339 100644
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -35,6 +35,7 @@ void ptrace_disable(struct task_struct *child)
 	user_disable_single_step(child);
 }
 
+#ifdef CONFIG_MMU
 long arch_ptrace(struct task_struct *child, long request,
 		 unsigned long addr, unsigned long data)
 {
@@ -150,3 +151,17 @@ void syscall_trace_leave(struct pt_regs *regs)
 	if (ptraced & PT_PTRACED)
 		set_thread_flag(TIF_SIGPENDING);
 }
+#else
+long arch_ptrace(struct task_struct *child, long request,
+		 unsigned long addr, unsigned long data)
+{
+	return -EINVAL;
+}
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *);
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+	BUG();
+	return 0;
+}
+#endif
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 6d8ae86ae978fd..5438cd7887980e 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -24,6 +24,7 @@
 int handle_page_fault(unsigned long address, unsigned long ip,
 		      int is_write, int is_user, int *code_out)
 {
+#ifdef CONFIG_MMU
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
 	pmd_t *pmd;
@@ -128,6 +129,7 @@ int handle_page_fault(unsigned long address, unsigned long ip,
 	if (!is_user)
 		goto out_nosemaphore;
 	pagefault_out_of_memory();
+#endif
 	return 0;
 }