diff --git a/arch/um/include/shared/sigio.h b/arch/um/include/shared/sigio.h
index 8fe8f57c05de8..e60c8b2278449 100644
--- a/arch/um/include/shared/sigio.h
+++ b/arch/um/include/shared/sigio.h
@@ -7,7 +7,6 @@
 #define __SIGIO_H__
 
 extern int write_sigio_irq(int fd);
-extern int register_sigio_fd(int fd);
 extern void sigio_lock(void);
 extern void sigio_unlock(void);