diff --git a/payloads/libpayload/libc/string.c b/payloads/libpayload/libc/string.c
index 9985749..a58efde 100644
--- a/payloads/libpayload/libc/string.c
+++ b/payloads/libpayload/libc/string.c
@@ -609,11 +609,15 @@
 	/* skip over prefix delimiters */
 	char *start = str + strspn(str, delim);
 
+	if (start[0] == '\0')
+		return NULL;
+
 	/* find first delimiter character */
 	char *end = start + strcspn(start, delim);
-	end[0] = '\0';
+	*ptr = end;
+	if (end[0] != '\0')
+		*(*ptr)++ = '\0';
 
-	*ptr = end+1;
 	return start;
 }