diff --git a/demo/custom.js b/demo/custom.js
index 1267cd8e25..ffd3b9612c 100644
--- a/demo/custom.js
+++ b/demo/custom.js
@@ -567,7 +567,7 @@ shakaDemo.Custom = class {
       this.manifestField_ = input;
     };
     const manifestOnChange = (input) => {
-      assetInProgress.manifestUri = input.value;
+      assetInProgress.manifestUri = input.value.trim();
     };
     const manifestURLName = shakaDemoMain.getLocalizedString(
         shakaDemo.MessageIds.MANIFEST_URL);