diff --git a/arch/um/sys-x86_64/delay.c b/arch/um/sys-x86_64/delay.c
index f3b5187..651332a 100644
--- a/arch/um/sys-x86_64/delay.c
+++ b/arch/um/sys-x86_64/delay.c
@@ -5,7 +5,9 @@
  * Licensed under the GPL
  */
 
+#include "linux/delay.h"
 #include "asm/processor.h"
+#include "asm/param.h"
 
 void __delay(unsigned long loops)
 {
@@ -14,6 +16,22 @@
 	for(i = 0; i < loops; i++) ;
 }
 
+void __udelay(unsigned long usecs)
+{
+	int i, n;
+
+	n = (loops_per_jiffy * HZ * usecs) / MILLION;
+	for(i=0;i<n;i++) ;
+}
+
+void __const_udelay(unsigned long usecs)
+{
+	int i, n;
+
+	n = (loops_per_jiffy * HZ * usecs) / MILLION;
+	for(i=0;i<n;i++) ;
+}
+
 /*
  * Overrides for Emacs so that we follow Linus's tabbing style.
  * Emacs will notice this stuff at the end of the file and automatically