diff --git a/sys/dev/hid/hidbus.c b/sys/dev/hid/hidbus.c
--- a/sys/dev/hid/hidbus.c
+++ b/sys/dev/hid/hidbus.c
@@ -604,7 +604,7 @@
 static int
 hidbus_intr_start(device_t bus, device_t child)
 {
-	MPASS(bus = device_get_parent(child));
+	MPASS(bus == device_get_parent(child));
 	struct hidbus_softc *sc = device_get_softc(bus);
 	struct hidbus_ivars *ivar = device_get_ivars(child);
 	struct hidbus_ivars *tlc;
@@ -630,7 +630,7 @@
 static int
 hidbus_intr_stop(device_t bus, device_t child)
 {
-	MPASS(bus = device_get_parent(child));
+	MPASS(bus == device_get_parent(child));
 	struct hidbus_softc *sc = device_get_softc(bus);
 	struct hidbus_ivars *ivar = device_get_ivars(child);
 	struct hidbus_ivars *tlc;