diff --git a/sys/external/bsd/drm/dist/shared-core/radeon_cp.c b/sys/external/bsd/drm/dist/shared-core/radeon_cp.c
index ae31e969dde9..f6601f1f8bf4 100644
--- a/sys/external/bsd/drm/dist/shared-core/radeon_cp.c
+++ b/sys/external/bsd/drm/dist/shared-core/radeon_cp.c
@@ -1389,6 +1389,9 @@ void radeon_do_release(struct drm_device * dev)
 #if defined(__FreeBSD__) && __FreeBSD_version > 500000
 				mtx_sleep(&ret, &dev->dev_lock, PZERO, "rdnrel",
 				       1);
+#elif defined(__NetBSD__)
+				mtsleep(&ret, PZERO, "rdnrel", 1, 
+					&dev->dev_lock);
 #else
 				tsleep(&ret, PZERO, "rdnrel", 1);
 #endif