diff --git a/sys/dev/tdfx/tdfx_pci.c b/sys/dev/tdfx/tdfx_pci.c
index 6c7a832fc20e..ff4efc6a8a25 100644
--- a/sys/dev/tdfx/tdfx_pci.c
+++ b/sys/dev/tdfx/tdfx_pci.c
@@ -823,4 +823,5 @@ static driver_t tdfx_driver = {
 
 /* Tell Mr. Kernel about us! */
 DRIVER_MODULE(tdfx, pci, tdfx_driver, tdfx_devclass, 0, 0);
+MODULE_DEPEND(tdfx, mem, 1, 1, 1);
 MODULE_VERSION(tdfx, 1);