diff --git a/command/command.go b/command/command.go
index 22f3158..b1b0697 100644
--- a/command/command.go
+++ b/command/command.go
@@ -36,7 +36,7 @@ const (
 	MaxRoleAdditionalContentLength = 1000 * 1000 // 1M of chars
 
 	MinMemberUserNameLength = 3
-	MaxMemberUserNameLength = 30
+	MaxMemberUserNameLength = 40
 	MinMemberFullNameLength = 3
 	MaxMemberFullNameLength = 100
 	MaxMemberEmailLength    = 100
@@ -52,7 +52,7 @@ const (
 	MaxRoleAssignmentFocusLength = 30
 )
 
-var UserNameRegexp = regexp.MustCompile(`^[a-zA-Z][a-zA-Z0-9]*([-]?[a-zA-Z0-9]+)+$`)
+var UserNameRegexp = regexp.MustCompile(`^[a-zA-Z][a-zA-Z0-9]*([-||.||_]?[a-zA-Z0-9]+)+$`)
 
 var (
 	ErrValidation = errors.New("validation error")
diff --git a/command/command_test.go b/command/command_test.go
index 252b679..23dffee 100644
--- a/command/command_test.go
+++ b/command/command_test.go
@@ -10,6 +10,10 @@ var (
 		"foo1",
 		"foo-1",
 		"foo-1-bar",
+		"foo.bar",
+		"foo_bar",
+		"foo.bar_hey",
+		"foo_bar.hello",
 		"f12oo-bar33",
 	}
 	badUserNames = []string{
@@ -18,10 +22,11 @@ var (
 		"-foo-bar",
 		"foo-bar-",
 		"foo--bar",
-		"foo.bar",
-		"foo_bar",
 		"foo#bar",
 		"1foobar",
+		"1foobar",
+		"_foobar",
+		".foobar",
 	}
 )