diff -r 3320a015a3bc -r 893a659768b3 dav/sync.c
--- a/dav/sync.c	Tue Feb 26 10:22:16 2019 +0100
+++ b/dav/sync.c	Tue Feb 26 10:29:14 2019 +0100
@@ -2105,7 +2105,7 @@
 }
 
 int gen_random_name(char *buf, size_t len) {
-    char name_prefix[8];
+    unsigned char name_prefix[8];
     memset(name_prefix, 0, 8);
     dav_rand_bytes(name_prefix, 8);   
     char *pre = util_hexstr(name_prefix, 8);