--- a/netwerk/base/CaptivePortalService.cpp
+++ b/netwerk/base/CaptivePortalService.cpp
@@ -80,16 +80,23 @@ CaptivePortalService::RearmTimer()
 {
   LOG(("CaptivePortalService::RearmTimer\n"));
   // Start a timer to recheck
   MOZ_ASSERT(XRE_GetProcessType() == GeckoProcessType_Default);
   if (mTimer) {
     mTimer->Cancel();
   }
 
+  // If we have successfully determined the state, and we have never detected
+  // a captive portal, we don't need to keep polling, but will rely on events
+  // to trigger detection.
+  if (mState == NOT_CAPTIVE) {
+    return NS_OK;
+  }
+
   if (!mTimer) {
     mTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
   }
 
   if (mTimer && mDelay > 0) {
     LOG(("CaptivePortalService - Reloading timer with delay %u\n", mDelay));
     return mTimer->InitWithCallback(this, mDelay, nsITimer::TYPE_ONE_SHOT);
   }