diff --git a/include/linux/acpi_pmtmr.h b/include/linux/acpi_pmtmr.h
index 1d0ef1a..7e3d285 100644
--- a/include/linux/acpi_pmtmr.h
+++ b/include/linux/acpi_pmtmr.h
@@ -25,6 +25,8 @@
 	return acpi_pm_read_verified() & ACPI_PM_MASK;
 }
 
+extern void pmtimer_wait(unsigned);
+
 #else
 
 static inline u32 acpi_pm_read_early(void)