diff --git a/Course3/Lab4/validations.py b/Course3/Lab4/validations.py
index b18de65a2e..063a5e7224 100644
--- a/Course3/Lab4/validations.py
+++ b/Course3/Lab4/validations.py
@@ -12,6 +12,9 @@ def validate_user(username, minlen):
     # Usernames can't be shorter than minlen
     if len(username) < minlen:
         return False
+    # Usernames can't begin with a period or an underscore
+    if username[0] == '.' or username[0] == '_':
+        return False
     # Usernames can only use letters, numbers, dots and underscores
     if not re.match('^[a-z0-9._]*$', username):
         return False
@@ -20,5 +23,10 @@ def validate_user(username, minlen):
         return False
     return True
 
+print(validate_user("blue.kale", 3)) # True
+print(validate_user(".blue.kale", 3)) # Currently True, should be False
+print(validate_user("red_quinoa", 4)) # True
+print(validate_user("_red_quinoa", 4)) # Currently True, should be False
+