--- a/browser/components/sessionstore/src/SessionStore.jsm
+++ b/browser/components/sessionstore/src/SessionStore.jsm
@@ -3706,19 +3706,16 @@ let SessionStoreInternal = {
       return;
     }
 
 #ifdef MOZ_PER_WINDOW_PRIVATE_BROWSING
     // Forget about private windows.
     for (let i = oState.windows.length - 1; i >= 0; i--) {
       if (oState.windows[i].isPrivate) {
         oState.windows.splice(i, 1);
-        if (oState.selectedWindow >= i) {
-          oState.selectedWindow--;
-        }
       }
     }
     for (let i = oState._closedWindows.length - 1; i >= 0; i--) {
       if (oState._closedWindows[i].isPrivate) {
         oState._closedWindows.splice(i, 1);
       }
     }
 #endif

--- a/browser/components/sessionstore/test/Makefile.in
+++ b/browser/components/sessionstore/test/Makefile.in
@@ -132,17 +132,16 @@ MOCHITEST_BROWSER_FILES = \
 	$(filter disabled-for-intermittent-failures--bug-766044, browser_459906_sample.html) \
 	$(filter disabled-for-intermittent-failures--bug-765389, browser_461743_sample.html) \
 	$(NULL)
 
 ifdef MOZ_PER_WINDOW_PRIVATE_BROWSING
 MOCHITEST_BROWSER_FILES += \
 	browser_354894_perwindowpb.js \
 	browser_394759_perwindowpb.js \
-	browser_819510_perwindowpb.js \
 	$(NULL)
 else
 MOCHITEST_BROWSER_FILES += \
 	browser_248970_a.js \
 	browser_248970_b.js \
 	browser_354894.js \
 	browser_394759_privatebrowsing.js \
 	$(NULL)

deleted file mode 100644
--- a/browser/components/sessionstore/test/browser_819510_perwindowpb.js
+++ /dev/null
@@ -1,171 +0,0 @@
-/* Any copyright is dedicated to the Public Domain.
-   http://creativecommons.org/publicdomain/zero/1.0/ */
-
-const originalState = ss.getBrowserState();
-
-/** Private Browsing Test for Bug 819510 **/
-function test() {
-  waitForExplicitFinish();
-
-  registerCleanupFunction(function() {
-    Services.prefs.clearUserPref("browser.sessionstore.interval");
-    ss.setBrowserState(originalState);
-  });
-
-  runNextTest();
-}
-
-let tests = [
-  test_1,
-  test_2,
-  test_3,
-];
-
-const testState = {
-  windows: [{
-    tabs: [
-      { entries: [{ url: "about:blank" }] },
-    ]
-  }]
-};
-
-function runNextTest() {
-  // Set an empty state
-  let windowsEnum = Services.wm.getEnumerator("navigator:browser");
-  while (windowsEnum.hasMoreElements()) {
-    let currentWindow = windowsEnum.getNext();
-    if (currentWindow != window) {
-      currentWindow.close();
-    }
-  }
-
-  // Run the next test, or finish
-  if (tests.length) {
-    let currentTest = tests.shift();
-    waitForBrowserState(testState, currentTest);
-  }
-  else {
-    Services.prefs.clearUserPref("browser.sessionstore.interval");
-    ss.setBrowserState(originalState);
-    finish();
-  }
-}
-
-// Test opening default mochitest-normal-private-normal-private windows
-// (saving the state with last window being private)
-function test_1() {
-  testOnWindow(false, function(aWindow) {
-    aWindow.gBrowser.addTab("http://www.example.com/1");
-    testOnWindow(true, function(aWindow) {
-      aWindow.gBrowser.addTab("http://www.example.com/2");
-      testOnWindow(false, function(aWindow) {
-        aWindow.gBrowser.addTab("http://www.example.com/3");
-        testOnWindow(true, function(aWindow) {
-          aWindow.gBrowser.addTab("http://www.example.com/4");
-
-          let curState = JSON.parse(ss.getBrowserState());
-          is (curState.windows.length, 5, "Browser has opened 5 windows");
-          is (curState.windows[2].isPrivate, true, "Window is private");
-          is (curState.windows[4].isPrivate, true, "Last window is private");
-          is (curState.selectedWindow, 5, "Last window opened is the one selected");
-
-          Services.obs.addObserver(function observe(aSubject, aTopic, aData) {
-            Services.obs.removeObserver(observe, aTopic);
-            aSubject.QueryInterface(Ci.nsISupportsString);
-            let state = JSON.parse(aSubject.data);
-            is(state.windows.length, 3,
-              "sessionstore state: 3 windows in data being writted to disk");
-            is (state.selectedWindow, 3,
-              "Selected window is updated to match one of the saved windows");
-            state.windows.forEach(function(win) {
-              is(!win.isPrivate, true, "Saved window is not private");
-            });
-            is(state._closedWindows.length, 0,
-              "sessionstore state: no closed windows in data being writted to disk");
-            runNextTest();
-          }, "sessionstore-state-write", false);
-
-          Services.prefs.setIntPref("browser.sessionstore.interval", 0);
-        });
-      });
-    });
-  });
-}
-
-// Test opening default mochitest window + 2 private windows
-function test_2() {
-testOnWindow(true, function(aWindow) {
-  aWindow.gBrowser.addTab("http://www.example.com/1");
-    testOnWindow(true, function(aWindow) {
-      aWindow.gBrowser.addTab("http://www.example.com/2");
-
-      let curState = JSON.parse(ss.getBrowserState());
-      is (curState.windows.length, 3, "Browser has opened 3 windows");
-      is (curState.windows[1].isPrivate, true, "Window 1 is private");
-      is (curState.windows[2].isPrivate, true, "Window 2 is private");
-      is (curState.selectedWindow, 3, "Last window opened is the one selected");
-
-      Services.obs.addObserver(function observe(aSubject, aTopic, aData) {
-        Services.obs.removeObserver(observe, aTopic);
-        aSubject.QueryInterface(Ci.nsISupportsString);
-        let state = JSON.parse(aSubject.data);
-        is(state.windows.length, 1,
-          "sessionstore state: 1 windows in data being writted to disk");
-        is (state.selectedWindow, 1,
-          "Selected window is updated to match one of the saved windows");
-        is(state._closedWindows.length, 0,
-          "sessionstore state: no closed windows in data being writted to disk");
-        runNextTest();
-      }, "sessionstore-state-write", false);
-      Services.prefs.setIntPref("browser.sessionstore.interval", 0);
-  });
-});
-}
-
-// Test opening default-normal-private-normal windows and closing a normal window
-function test_3() {
-  testOnWindow(false, function(normalWindow) {
-    normalWindow.gBrowser.addTab("http://www.example.com/1");
-    testOnWindow(true, function(aWindow) {
-      aWindow.gBrowser.addTab("http://www.example.com/2");
-      testOnWindow(false, function(aWindow) {
-        aWindow.gBrowser.addTab("http://www.example.com/3");
-
-        let curState = JSON.parse(ss.getBrowserState());
-        is (curState.windows.length, 4, "Browser has opened 4 windows");
-        is (curState.windows[2].isPrivate, true, "Window 2 is private");
-        is (curState.selectedWindow, 4, "Last window opened is the one selected");
-
-        normalWindow.close();
-        Services.obs.addObserver(function observe(aSubject, aTopic, aData) {
-          Services.obs.removeObserver(observe, aTopic);
-          aSubject.QueryInterface(Ci.nsISupportsString);
-          let state = JSON.parse(aSubject.data);
-          is(state.windows.length, 2,
-            "sessionstore state: 2 windows in data being writted to disk");
-          is (state.selectedWindow, 2,
-            "Selected window is updated to match one of the saved windows");
-          state.windows.forEach(function(win) {
-            is(!win.isPrivate, true, "Saved window is not private");
-          });
-          is(state._closedWindows.length, 1,
-            "sessionstore state: 1 closed window in data being writted to disk");
-          state._closedWindows.forEach(function(win) {
-            is(!win.isPrivate, true, "Closed window is not private");
-          });
-          runNextTest();
-        }, "sessionstore-state-write", false);
-
-        Services.prefs.setIntPref("browser.sessionstore.interval", 0);
-      });
-    });
-  });
-}
-
-function testOnWindow(aIsPrivate, aCallback) {
-  let win = OpenBrowserWindow({private: aIsPrivate});
-  win.addEventListener("load", function onLoad() {
-    win.removeEventListener("load", onLoad, false);
-    executeSoon(function() { aCallback(win); });
-  }, false);
-}