diff --git a/src/Liquid/StandardFilters.php b/src/Liquid/StandardFilters.php
index bb02cdf..c3e274d 100644
--- a/src/Liquid/StandardFilters.php
+++ b/src/Liquid/StandardFilters.php
@@ -202,7 +202,7 @@ public static function escape($input)
 		}
 
 		if (is_null($input)) {
-			return $input;
+			return '';
 		}
 
 		return htmlentities($input, ENT_QUOTES);
diff --git a/tests/Liquid/StandardFiltersTest.php b/tests/Liquid/StandardFiltersTest.php
index 7b51904..701e999 100644
--- a/tests/Liquid/StandardFiltersTest.php
+++ b/tests/Liquid/StandardFiltersTest.php
@@ -231,7 +231,7 @@ public function testEscape()
 		$data = array(
 			"one Word's not" => "one Word's not",
 			"&><\"'" => "&amp;&gt;&lt;&quot;&#039;",
-			null => null,
+			null => '',
 		);
 
 		foreach ($data as $element => $expected) {