diff --git a/timesheet.py b/timesheet.py
index 2e5e0553a2..67ee5cc324 100644
--- a/timesheet.py
+++ b/timesheet.py
@@ -17,7 +17,7 @@ class TimesheetLine:
     def __setup__(cls):
         super(TimesheetLine, cls).__setup__()
         cls._error_messages.update({
-                'delete_invoiced_line': 'You can not delete invoiced line',
+                'delete_invoiced_line': 'You can not delete invoiced line.',
                 })
 
     @classmethod
diff --git a/work.py b/work.py
index ed63ec75b1..7903b39d88 100644
--- a/work.py
+++ b/work.py
@@ -68,9 +68,9 @@ class Work:
                     },
                 })
         cls._error_messages.update({
-                'missing_product': 'There is no product on work "%s"',
-                'missing_list_price': 'There is no list price on work "%s"',
-                'missing_party': 'There is no party on work "%s"',
+                'missing_product': 'There is no product on work "%s".',
+                'missing_list_price': 'There is no list price on work "%s".',
+                'missing_party': 'There is no party on work "%s".',
                 })
 
     @staticmethod