diff --git a/SourceGithub/SourceGithub.php b/SourceGithub/SourceGithub.php
index c06e28c..71ca2c6 100644
--- a/SourceGithub/SourceGithub.php
+++ b/SourceGithub/SourceGithub.php
@@ -162,7 +162,7 @@
 		$f_hub_reponame = gpc_get_string( 'hub_reponame' );
 		$f_master_branch = gpc_get_string( 'master_branch' );
 
-		if ( !preg_match( '/^[a-zA-Z0-9_, -]*$/', $f_master_branch ) ) {
+		if ( !preg_match( '/^[a-zA-Z0-9_\., -]*$/', $f_master_branch ) ) {
 			echo 'Invalid parameter: \'Primary Branch\'';
 			trigger_error( ERROR_GENERIC, ERROR );
 		}