diff --git a/sys/dev/agp/agp_amd.c b/sys/dev/agp/agp_amd.c
index 16125fb3990c..198b926241fb 100644
--- a/sys/dev/agp/agp_amd.c
+++ b/sys/dev/agp/agp_amd.c
@@ -246,6 +246,11 @@ static int
 agp_amd_detach(device_t dev)
 {
 	struct agp_amd_softc *sc = device_get_softc(dev);
+	int error;
+
+	error = agp_generic_detach(dev);
+	if (error)
+		return error;
 
 	/* Disable the TLB.. */
 	WRITE2(AGP_AMD751_STATUS,
@@ -261,6 +266,10 @@ agp_amd_detach(device_t dev)
 	AGP_SET_APERTURE(dev, sc->initial_aperture);
 
 	agp_amd_free_gatt(sc->gatt);
+
+	bus_release_resource(dev, SYS_RES_MEMORY,
+			     AGP_AMD751_REGISTERS, sc->regs);
+
 	return 0;
 }
 
diff --git a/sys/pci/agp_amd.c b/sys/pci/agp_amd.c
index 16125fb3990c..198b926241fb 100644
--- a/sys/pci/agp_amd.c
+++ b/sys/pci/agp_amd.c
@@ -246,6 +246,11 @@ static int
 agp_amd_detach(device_t dev)
 {
 	struct agp_amd_softc *sc = device_get_softc(dev);
+	int error;
+
+	error = agp_generic_detach(dev);
+	if (error)
+		return error;
 
 	/* Disable the TLB.. */
 	WRITE2(AGP_AMD751_STATUS,
@@ -261,6 +266,10 @@ agp_amd_detach(device_t dev)
 	AGP_SET_APERTURE(dev, sc->initial_aperture);
 
 	agp_amd_free_gatt(sc->gatt);
+
+	bus_release_resource(dev, SYS_RES_MEMORY,
+			     AGP_AMD751_REGISTERS, sc->regs);
+
 	return 0;
 }