diff --git a/src/js/findSlave.js b/src/js/findSlave.js
index bd138ce9bdcad7685308e764fd152f2068582594..c0f8f9e39d452aa611f1a13d5f77106ad5a88afa 100644
--- a/src/js/findSlave.js
+++ b/src/js/findSlave.js
@@ -7,8 +7,8 @@ App.FindSlave = {};
  * @returns {boolean}
  */
 App.FindSlave._fragmentSearch = function(haystacks, needles) {
-	const hs = haystacks.join(" ");
-	return needles.every((needle) => { return needle.test(hs); });
+	const hs = haystacks.filter(h => !!h).join(" ");
+	return needles.every((needle) => needle.test(hs));
 };
 
 /**