--- a/browser/modules/BrowserUsageTelemetry.jsm
+++ b/browser/modules/BrowserUsageTelemetry.jsm
@@ -93,16 +93,20 @@ function getOpenTabsAndWinsCounts() {
     let win = browserEnum.getNext();
     winCount++;
     tabCount += win.gBrowser.tabs.length;
   }
 
   return { tabCount, winCount };
 }
 
+function getTabCount() {
+  return getOpenTabsAndWinsCounts().tabCount;
+}
+
 function getSearchEngineId(engine) {
   if (engine) {
     if (engine.identifier) {
       return engine.identifier;
     }
     // Due to bug 1222070, we can't directly check Services.telemetry.canRecordExtended
     // here.
     const extendedTelemetry = Services.prefs.getBoolPref("toolkit.telemetry.enabled");
@@ -630,9 +634,13 @@ let BrowserUsageTelemetry = {
       Services.telemetry.scalarSetMaximum(MAX_WINDOW_COUNT_SCALAR_NAME, counts.winCount);
 
       // We won't receive the "TabOpen" event for the first tab within a new window.
       // Account for that.
       this._onTabOpen(counts.tabCount);
     };
     win.addEventListener("load", onLoad);
   },
+
+  _recordTabCount(tabCount = getTabCount()) {
+    Services.telemetry.getHistogramById("TAB_COUNT").add(tabCount);
+  },
 };