diff --git a/browser/devtools/netmonitor/test/browser_net_filter-02.js b/browser/devtools/netmonitor/test/browser_net_filter-02.js
index fc1775052b62..2ab70bee08bd 100644
--- a/browser/devtools/netmonitor/test/browser_net_filter-02.js
+++ b/browser/devtools/netmonitor/test/browser_net_filter-02.js
@@ -9,6 +9,9 @@ function test() {
   initNetMonitor(FILTERING_URL).then(([aTab, aDebuggee, aMonitor]) => {
     info("Starting test... ");
 
+    // It seems that this test may be slow on Ubuntu builds running on ec2.
+    requestLongerTimeout(2);
+
     let { $, NetMonitorView } = aMonitor.panelWin;
     let { RequestsMenu } = NetMonitorView;