diff --git a/lib/libusb/libusb20.c b/lib/libusb/libusb20.c
index 1de3a265125a..2eb75f1c6d7c 100644
--- a/lib/libusb/libusb20.c
+++ b/lib/libusb/libusb20.c
@@ -139,8 +139,8 @@ libusb20_tr_close(struct libusb20_transfer *xfer)
 		free(xfer->ppBuffer);
 	}
 	/* reset variable fields in case the transfer is opened again */
-	xfer->priv_sc0 = 0;
-	xfer->priv_sc1 = 0;
+	xfer->priv_sc0 = NULL;
+	xfer->priv_sc1 = NULL;
 	xfer->is_opened = 0;
 	xfer->is_pending = 0;
 	xfer->is_cancel = 0;
diff --git a/lib/libusbhid/descr.c b/lib/libusbhid/descr.c
index 0c6634236635..4ca9dd795d09 100644
--- a/lib/libusbhid/descr.c
+++ b/lib/libusbhid/descr.c
@@ -159,7 +159,7 @@ hid_use_report_desc(unsigned char *data, unsigned int size)
 	report_desc_t r;
 
 	r = malloc(sizeof(*r) + size);
-	if (r == 0) {
+	if (r == NULL) {
 		errno = ENOMEM;
 		return (NULL);
 	}
diff --git a/lib/libusbhid/usage.c b/lib/libusbhid/usage.c
index eeff818afed8..3960dad8076a 100644
--- a/lib/libusbhid/usage.c
+++ b/lib/libusbhid/usage.c
@@ -77,9 +77,9 @@ hid_init(const char *hidname)
 	char line[100], name[100], *p, *n;
 	int no;
 	int lineno;
-	struct usage_page *curpage = 0;
+	struct usage_page *curpage = NULL;
 
-	if (hidname == 0)
+	if (hidname == NULL)
 		hidname = _PATH_HIDTABLE;
 
 	f = fopen(hidname, "r");
@@ -124,7 +124,7 @@ hid_init(const char *hidname)
 			curpage->pagesize++;
 		} else {
 			if (npages >= npagesmax) {
-				if (pages == 0) {
+				if (pages == NULL) {
 					npagesmax = 5;
 					pages = malloc(npagesmax *
 						  sizeof (struct usage_page));
diff --git a/sys/dev/usb/net/if_urndis.c b/sys/dev/usb/net/if_urndis.c
index 749f874c0d94..de7fd1e4b335 100644
--- a/sys/dev/usb/net/if_urndis.c
+++ b/sys/dev/usb/net/if_urndis.c
@@ -235,7 +235,7 @@ urndis_attach(device_t dev)
 
 	cmd = usbd_find_descriptor(uaa->device, NULL, uaa->info.bIfaceIndex,
 	    UDESC_CS_INTERFACE, 0xFF, UDESCSUB_CDC_CM, 0xFF);
-	if (cmd != 0) {
+	if (cmd != NULL) {
 		DPRINTF("Call Mode Descriptor found, dataif=%d\n", cmd->bDataInterface);
 		iface_index[0] = cmd->bDataInterface;
 	}
diff --git a/sys/dev/usb/usb_transfer.c b/sys/dev/usb/usb_transfer.c
index 783a96c017b2..17b9367df4b7 100644
--- a/sys/dev/usb/usb_transfer.c
+++ b/sys/dev/usb/usb_transfer.c
@@ -925,7 +925,7 @@ usbd_transfer_setup(struct usb_device *udev,
 		DPRINTFN(6, "setup array has zero length!\n");
 		return (USB_ERR_INVAL);
 	}
-	if (ifaces == 0) {
+	if (ifaces == NULL) {
 		DPRINTFN(6, "ifaces array is NULL!\n");
 		return (USB_ERR_INVAL);
 	}