diff --git a/CHANGES.rst b/CHANGES.rst
index 0d7eb6b4d4..b416ff3e09 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -4,6 +4,7 @@ Changelog
 2.4.0 (unreleased)
 ------------------
 
+- #2173 Fix UnicodeDecodeError when a required condition is empty in add form
 - #2172 Fix SuperModel import error introduced in PR #2154
 - #2169 Fix field error indication in sample header
 - #2166 Fix partitions not displaying complete list of Interpretation Templates
diff --git a/src/bika/lims/browser/analysisrequest/add2.py b/src/bika/lims/browser/analysisrequest/add2.py
index 1f121e2a5b..a201267ee1 100644
--- a/src/bika/lims/browser/analysisrequest/add2.py
+++ b/src/bika/lims/browser/analysisrequest/add2.py
@@ -1617,7 +1617,7 @@ def ajax_submit(self):
             # If there are required fields missing, flag an error
             for field in missing:
                 fieldname = "{}-{}".format(field, n)
-                msg = _("Field '{}' is required".format(field))
+                msg = _("Field '{}' is required").format(safe_unicode(field))
                 fielderrors[fieldname] = msg
 
             # Process valid record