diff --git a/namedev.c b/namedev.c
index 7c07e3b1042..581a7f2218c 100644
--- a/namedev.c
+++ b/namedev.c
@@ -263,11 +263,11 @@ static void apply_format(struct udevice *udev, char *string, size_t maxsize,
 			dbg("substitute kernel number '%s'", udev->kernel_number);
 				break;
 		case 'm':
-			sprintf(pos, "%u", udev->minor);
+			strnintcat(string, udev->minor, maxsize);
 			dbg("substitute minor number '%u'", udev->minor);
 			break;
-			case 'M':
-			sprintf(pos, "%u", udev->major);
+		case 'M':
+			strnintcat(string, udev->major, maxsize);
 			dbg("substitute major number '%u'", udev->major);
 			break;
 		case 'c':
diff --git a/udev-add.c b/udev-add.c
index 8fdd66fad52..3a72c544b8b 100644
--- a/udev-add.c
+++ b/udev-add.c
@@ -211,7 +211,8 @@ static int create_node(struct udevice *dev, int fake)
 		info("creating device partition nodes '%s[1-%i]'", filename, dev->partitions);
 		if (!fake) {
 			for (i = 1; i <= dev->partitions; i++) {
-				sprintf(partitionname, "%s%i", filename, i);
+				strfieldcpy(partitionname, filename);
+				strintcat(partitionname, i);
 				make_node(partitionname, dev->major,
 					  dev->minor + i, dev->mode, uid, gid);
 			}
diff --git a/udev-remove.c b/udev-remove.c
index 8794429635b..e62d1fb1223 100644
--- a/udev-remove.c
+++ b/udev-remove.c
@@ -87,7 +87,8 @@ static int delete_node(struct udevice *dev)
 	if (dev->partitions > 0) {
 		info("removing partitions '%s[1-%i]'", filename, dev->partitions);
 		for (i = 1; i <= dev->partitions; i++) {
-			sprintf(partitionname, "%s%i", filename, i);
+			strfieldcpy(partitionname, filename);
+			strintcat(partitionname, i);
 			unlink(partitionname);
 		}
 	}
diff --git a/udev.h b/udev.h
index 3b676acf40d..5737c84c9d1 100644
--- a/udev.h
+++ b/udev.h
@@ -85,6 +85,18 @@ do { \
 	strncat(to, from, maxsize - strlen(to)-1); \
 } while (0)
 
+#define strintcat(to, i) \
+do { \
+	to[sizeof(to)-1] = '\0'; \
+	snprintf((to) + strlen(to), sizeof(to) - strlen(to)-1, "%u", i); \
+} while (0)
+
+#define strnintcat(to, i, maxsize) \
+do { \
+	to[maxsize-1] = '\0'; \
+	snprintf((to) + strlen(to), maxsize - strlen(to)-1, "%u", i); \
+} while (0)
+
 static inline char *get_action(void)
 {
 	char *action;