diff --git a/testing/taskcluster/tasks/tests/b2g_emulator_xpcshell.yml b/testing/taskcluster/tasks/tests/b2g_emulator_xpcshell.yml
index 9733da3c206b..c02afe9b0581 100644
--- a/testing/taskcluster/tasks/tests/b2g_emulator_xpcshell.yml
+++ b/testing/taskcluster/tasks/tests/b2g_emulator_xpcshell.yml
@@ -7,6 +7,7 @@ task:
     description: XPCShell test run
 
   payload:
+    maxRunTime: 6000
     command:
       - entrypoint
       - >
diff --git a/testing/taskcluster/tasks/tests/b2g_emulator_xpcshell_chunked.yml b/testing/taskcluster/tasks/tests/b2g_emulator_xpcshell_chunked.yml
index abe3314b9231..f0de7d1c707a 100644
--- a/testing/taskcluster/tasks/tests/b2g_emulator_xpcshell_chunked.yml
+++ b/testing/taskcluster/tasks/tests/b2g_emulator_xpcshell_chunked.yml
@@ -7,6 +7,7 @@ task:
     description: XPCShell test run {{chunk}}
 
   payload:
+    maxRunTime: 6000
     command:
       - entrypoint
       - >