diff --git a/test/TriGParserTest.php b/test/TriGParserTest.php
index 6d0e52b..6d31541 100644
--- a/test/TriGParserTest.php
+++ b/test/TriGParserTest.php
@@ -69,7 +69,7 @@ public function shouldNotParse($createParser, $input, $expectedError = null): vo
                 $this->fail("Expected this error to be thrown (but it wasn't): ".$expectedError);
             }
         });
-        if (!$errorReceived) {
+        if (false === $errorReceived) {
             $this->fail("Expected this error to be thrown (but it wasn't): ".$expectedError);
         }
     }