diff --git a/lib/NGCP/Panel.pm b/lib/NGCP/Panel.pm
index 0d106a3d6b..7daea5544d 100644
--- a/lib/NGCP/Panel.pm
+++ b/lib/NGCP/Panel.pm
@@ -63,7 +63,7 @@ $logger_config = $panel_config unless(defined $logger_config);
 
 sub handle_unicode_encoding_exception {
     my ($self, $exception_context) = @_;
-    $self->log->debug(">> handle_unicode_encoding_exception: ", $exception_context->{error_msg});
+    $self->log->debug(">> handle_unicode_encoding_exception: " . $exception_context->{error_msg});
     return $exception_context->{param_value};
 }