Fix PHP8 deprecation warning

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/less.php/Less.php b/lib/less.php/Less.php
index 89a4877..3616cb4 100644
--- a/lib/less.php/Less.php
+++ b/lib/less.php/Less.php
@@ -8097,7 +8097,7 @@ class Less_Tree_Mixin_Call extends Less_Tree{
 			} else {
 				$defaultResult = $defTrue;
 				if( ($count[$defTrue] + $count[$defFalse]) > 1 ){
-					throw new Exception( 'Ambiguous use of `default()` found when matching for `'. $this->format($args) + '`' );
+					throw new Exception( 'Ambiguous use of `default()` found when matching for `'. $this->format($args) . '`' );
 				}
 			}