diff --git a/toolkit/components/startup/nsAppStartup.cpp b/toolkit/components/startup/nsAppStartup.cpp
index e2511dd045f9..9dad4574fc7e 100644
--- a/toolkit/components/startup/nsAppStartup.cpp
+++ b/toolkit/components/startup/nsAppStartup.cpp
@@ -127,7 +127,8 @@ public:
  * @param stamp The timestamp to be converted
  * @returns The converted timestamp
  */
-uint64_t ComputeAbsoluteTimestamp(PRTime prnow, TimeStamp now, TimeStamp stamp)
+static uint64_t
+ComputeAbsoluteTimestamp(TimeStamp stamp)
 {
   static PRTime sAbsoluteNow = PR_Now();
   static TimeStamp sMonotonicNow = TimeStamp::Now();
@@ -756,8 +757,6 @@ nsAppStartup::GetStartupInfo(JSContext* aCx, JS::MutableHandle<JS::Value> aRetva
   aRetval.setObject(*obj);
 
   TimeStamp procTime = StartupTimeline::Get(StartupTimeline::PROCESS_CREATION);
-  TimeStamp now = TimeStamp::Now();
-  PRTime absNow = PR_Now();
 
   if (procTime.IsNull()) {
     bool error = false;
@@ -789,7 +788,7 @@ nsAppStartup::GetStartupInfo(JSContext* aCx, JS::MutableHandle<JS::Value> aRetva
 
     if (!stamp.IsNull()) {
       if (stamp >= procTime) {
-        PRTime prStamp = ComputeAbsoluteTimestamp(absNow, now, stamp)
+        PRTime prStamp = ComputeAbsoluteTimestamp(stamp)
           / PR_USEC_PER_MSEC;
         JS::Rooted<JSObject*> date(aCx, JS::NewDateObject(aCx, JS::TimeClip(prStamp)));
         JS_DefineProperty(aCx, obj, StartupTimeline::Describe(ev), date, JSPROP_ENUMERATE);
@@ -943,14 +942,12 @@ nsAppStartup::TrackStartupCrashEnd()
   // Use the timestamp of XRE_main as an approximation for the lock file timestamp.
   // See MAX_STARTUP_BUFFER for the buffer time period.
   TimeStamp mainTime = StartupTimeline::Get(StartupTimeline::MAIN);
-  TimeStamp now = TimeStamp::Now();
-  PRTime prNow = PR_Now();
   nsresult rv;
 
   if (mainTime.IsNull()) {
     NS_WARNING("Could not get StartupTimeline::MAIN time.");
   } else {
-    uint64_t lockFileTime = ComputeAbsoluteTimestamp(prNow, now, mainTime);
+    uint64_t lockFileTime = ComputeAbsoluteTimestamp(mainTime);
 
     rv = Preferences::SetInt(kPrefLastSuccess,
       (int32_t)(lockFileTime / PR_USEC_PER_SEC));