diff --git a/lib/index.js b/lib/index.js
index c6ab89c..ffe02fa 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -175,7 +175,7 @@ function processNode (node, valueOnly = false) {
           node.alternate
             ? processNode(node.alternate)
             : undefined
-        ].filter(Boolean)
+        ].filter(item => item !== undefined)
       }
     }