diff --git a/README.md b/README.md
index aafb966..547b336 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,8 @@ At the moment, an alpha version is undertaken, with these features:
 - Works are shown sorted by composer and opus/work_directory-number (`s`, `smo`) or by composer and collection (`sm`)
 - Remove work or movement from being mastered for active user (`r number_of_work` or `r number_of_work number_of_movement`)
 - Remove user (`delete_my_user_record_including_all_mastered_works`)
-- Fix bug: double marking crashes the program
+- Fixed bug: double marking crashes the program
+- Fixed bug: check for user before setting
 
 _(planned) Release piano_repertoire_cli V 0.0.1 alpha (learn about versioning before)_
 
@@ -44,6 +45,5 @@ _(planned) Port funtionality to a kivy-GUI_
 
 ## Known Bugs
 
-- User numbers are allowed to set without a user being present, with marking works as mastered leading to crash the program
 - Trying to mark works as mastered that are not present crashes the program
 - Providing alphabetic chars where numbers are expected crashes the program
\ No newline at end of file
diff --git a/rep_cli.py b/rep_cli.py
index 28d7010..6d03f8a 100644
--- a/rep_cli.py
+++ b/rep_cli.py
@@ -23,9 +23,19 @@ class Session:
                         }
 
     def set_user(self, arguments):
+        resultstring = ''
         db_index = arguments[0]
-        self.user = db_index
-        return 'User set'
+        sql_command = f'''
+                      SELECT *
+                      FROM pianist
+                      WHERE id = {db_index}
+                      '''
+        if self.db_agent.execute(sql_command).fetchone():
+            self.user = db_index
+            resultstring += 'User set'
+        else:
+            resultstring += 'No such user' 
+        return resultstring
 
     def get_active_user(self):
         sql_command = f'''