diff --git a/sys/dev/drm2/radeon/radeon_acpi.c b/sys/dev/drm2/radeon/radeon_acpi.c
index a725ab78624e..e4dd6e846945 100644
--- a/sys/dev/drm2/radeon/radeon_acpi.c
+++ b/sys/dev/drm2/radeon/radeon_acpi.c
@@ -32,8 +32,6 @@ __FBSDID("$FreeBSD$");
 
 #define ACPI_AC_CLASS           "ac_adapter"
 
-extern void radeon_pm_acpi_event_handler(struct radeon_device *rdev);
-
 struct atif_verify_interface {
 	u16 size;		/* structure size in bytes (includes size field) */
 	u16 version;		/* version */