diff --git a/lib/checks/keyboard/tabindex.js b/lib/checks/keyboard/tabindex.js
index aaf98a6717..ddfdc7ed51 100644
--- a/lib/checks/keyboard/tabindex.js
+++ b/lib/checks/keyboard/tabindex.js
@@ -1,4 +1,4 @@
-const tabIndex = parseInt(node.getAttribute('tabindex'));
+const tabIndex = parseInt(node.getAttribute('tabindex'), 10);
 
 // an invalid tabindex will either return 0 or -1 (based on the element) so
 // will never be above 0