diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index 92a7b59120d6..2d9d2ca39299 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -239,6 +239,7 @@ int __init can_drop_memory(void)
 	return ok;
 }
 
+#ifdef UML_CONFIG_MODE_TT
 void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int))
 {
 	int flags = 0, pages;
@@ -260,6 +261,7 @@ void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int))
 			      "errno = %d\n", errno);
 	}
 }
+#endif
 
 void init_new_thread_signals(void)
 {