diff --git a/arch/x86/um/ldt.c b/arch/x86/um/ldt.c
index 9701a4fd7bf2e..836a1eb5df436 100644
--- a/arch/x86/um/ldt.c
+++ b/arch/x86/um/ldt.c
@@ -12,7 +12,10 @@
 #include <skas.h>
 #include <sysdep/tls.h>
 
-extern int modify_ldt(int func, void *ptr, unsigned long bytecount);
+static inline int modify_ldt (int func, void *ptr, unsigned long bytecount)
+{
+	return syscall(__NR_modify_ldt, func, ptr, bytecount);
+}
 
 static long write_ldt_entry(struct mm_id *mm_idp, int func,
 		     struct user_desc *desc, void **addr, int done)