diff --git a/compat.c b/compat.c
index 19f1d13..48d486a 100644
--- a/compat.c
+++ b/compat.c
@@ -439,6 +439,9 @@ int id3_compat_fixup(struct id3_tag *tag)
     encoding = id3_parse_uint(&data, 1);
     string   = id3_parse_string(&data, end - data, encoding, 0);
 
+       if (!string)
+               continue;
+
     if (id3_ucs4_length(string) < 4) {
       free(string);
       continue;
diff --git a/ucs4.c b/ucs4.c
index f55f159..9d2e02b 100644
--- a/ucs4.c
+++ b/ucs4.c
@@ -37,6 +37,9 @@ id3_ucs4_t const id3_ucs4_empty[] = { 0 };
  */
 id3_length_t id3_ucs4_length(id3_ucs4_t const *ucs4)
 {
+       if (!ucs4)
+               return 0;
+
   id3_ucs4_t const *ptr = ucs4;
 
   while (*ptr)