diff --git a/drivers/isdn/gigaset/ev-layer.c b/drivers/isdn/gigaset/ev-layer.c
index a14187605f5e477549b11143d5da129c55aec9b0..ba74646cf0e481fd2b6741fc4d012aa1cb5a2fc5 100644
--- a/drivers/isdn/gigaset/ev-layer.c
+++ b/drivers/isdn/gigaset/ev-layer.c
@@ -390,12 +390,12 @@ static const struct zsau_resp_t {
  */
 static int cid_of_response(char *s)
 {
-	unsigned long cid;
+	int cid;
 	int rc;
 
 	if (s[-1] != ';')
 		return 0;	/* no CID separator */
-	rc = strict_strtoul(s, 10, &cid);
+	rc = kstrtoint(s, 10, &cid);
 	if (rc)
 		return 0;	/* CID not numeric */
 	if (cid < 1 || cid > 65535)
@@ -566,27 +566,19 @@ void gigaset_handle_modem_response(struct cardstate *cs)
 		case RT_ZCAU:
 			event->parameter = -1;
 			if (curarg + 1 < params) {
-				unsigned long type, value;
-
-				i = strict_strtoul(argv[curarg++], 16, &type);
-				j = strict_strtoul(argv[curarg++], 16, &value);
+				u8 type, value;
 
-				if (i == 0 && type < 256 &&
-				    j == 0 && value < 256)
+				i = kstrtou8(argv[curarg++], 16, &type);
+				j = kstrtou8(argv[curarg++], 16, &value);
+				if (i == 0 && j == 0)
 					event->parameter = (type << 8) | value;
 			} else
 				curarg = params - 1;
 			break;
 		case RT_NUMBER:
-			event->parameter = -1;
-			if (curarg < params) {
-				unsigned long res;
-				int rc;
-
-				rc = strict_strtoul(argv[curarg++], 10, &res);
-				if (rc == 0)
-					event->parameter = res;
-			}
+			if (curarg >= params ||
+			    kstrtoint(argv[curarg++], 10, &event->parameter))
+				event->parameter = -1;
 			gig_dbg(DEBUG_EVENT, "parameter==%d", event->parameter);
 			break;
 		}
diff --git a/drivers/isdn/hysdn/hysdn_proclog.c b/drivers/isdn/hysdn/hysdn_proclog.c
index 2ee93d04b2dd688ffd92690e6d4f4a6baaafee0b..236cc7dadfd09ff13ad6646e1dcfb818dba81efa 100644
--- a/drivers/isdn/hysdn/hysdn_proclog.c
+++ b/drivers/isdn/hysdn/hysdn_proclog.c
@@ -155,7 +155,6 @@ put_log_buffer(hysdn_card * card, char *cp)
 static ssize_t
 hysdn_log_write(struct file *file, const char __user *buf, size_t count, loff_t * off)
 {
-	unsigned long u = 0;
 	int rc;
 	unsigned char valbuf[128];
 	hysdn_card *card = file->private_data;
@@ -167,12 +166,10 @@ hysdn_log_write(struct file *file, const char __user *buf, size_t count, loff_t
 
 	valbuf[count] = 0;	/* terminating 0 */
 
-	rc = strict_strtoul(valbuf, 0, &u);
-
-	if (rc == 0) {
-		card->debug_flags = u;	/* remember debug flags */
-		hysdn_addlog(card, "debug set to 0x%lx", card->debug_flags);
-	}
+	rc = kstrtoul(valbuf, 0, &card->debug_flags);
+	if (rc < 0)
+		return rc;
+	hysdn_addlog(card, "debug set to 0x%lx", card->debug_flags);
 	return (count);
 }				/* hysdn_log_write */