diff --git a/gramps/gen/utils/grampslocale.py b/gramps/gen/utils/grampslocale.py
index b9f12cfa4..ecc00f6a0 100644
--- a/gramps/gen/utils/grampslocale.py
+++ b/gramps/gen/utils/grampslocale.py
@@ -33,6 +33,7 @@ import codecs
 import locale
 import collections
 import logging
+from binascii import hexlify
 
 LOG = logging.getLogger("." + __name__)
 LOG.propagate = True
@@ -920,8 +921,9 @@ class GrampsLocale:
         """
 
         if HAVE_ICU and self.collator:
-            #ICU can digest strings and unicode
-            return self.collator.getCollationKey(string).getByteArray()
+            # ICU can digest strings and unicode
+            # Use hexlify() as to make a consistent string, fixing bug #10077
+            return hexlify(self.collator.getCollationKey(string).getByteArray()).decode()
         else:
             if isinstance(string, bytes):
                 string = string.decode("utf-8", "replace")