diff --git a/pdo-debug.php b/pdo-debug.php
index 8ee7400..470ac7d 100644
--- a/pdo-debug.php
+++ b/pdo-debug.php
@@ -51,6 +51,10 @@ static public function show($raw_sql, $parameters)
                 $values[] = implode(',', $value);
             } elseif (is_null($value)) {
                 $values[] = 'NULL';
+            } elseif (is_bool($value)) {
+                $values[] = strval($value);
+            } else {
+                $values[] = strval($value);
             }
         }
         if ($isNamedMarkers) {