diff --git a/ResultPrinter.php b/ResultPrinter.php
index 6bc41cf..6d3136e 100644
--- a/ResultPrinter.php
+++ b/ResultPrinter.php
@@ -42,7 +42,7 @@ class ResultPrinter extends PPrinter
     protected $numTestsRun;
 
     /** @var int  */
-    protected $numTests;
+    protected $numTests = -1;
 
     /** @var int  */
     protected $column;