diff --git a/docshell/test/navigation/browser.ini b/docshell/test/navigation/browser.ini
index 64c36bf252ec..59b3ad23aa87 100644
--- a/docshell/test/navigation/browser.ini
+++ b/docshell/test/navigation/browser.ini
@@ -11,3 +11,4 @@ support-files =
 [browser_bug343515.js]
 [browser_test-content-chromeflags.js]
 tags = openwindow
+[browser_ghistorymaxsize_is_0.js]
diff --git a/docshell/test/navigation/browser_ghistorymaxsize_is_0.js b/docshell/test/navigation/browser_ghistorymaxsize_is_0.js
new file mode 100644
index 000000000000..db5385eb59c0
--- /dev/null
+++ b/docshell/test/navigation/browser_ghistorymaxsize_is_0.js
@@ -0,0 +1,60 @@
+add_task(async function() {
+  // The urls don't really matter as long as they are of the same origin
+  var URL =
+    "http://mochi.test:8888/browser/docshell/test/navigation/bug343515_pg1.html";
+  var URL2 =
+    "http://mochi.test:8888/browser/docshell/test/navigation/bug343515_pg3_1.html";
+
+  // We want to test a specific code path that leads to this call
+  // https://searchfox.org/mozilla-central/rev/e7c61f4a68b974d5fecd216dc7407b631a24eb8f/docshell/base/nsDocShell.cpp#10795
+  // when gHistoryMaxSize is 0 and mIndex and mRequestedIndex are -1
+
+  // 1. Navigate to URL
+  await BrowserTestUtils.withNewTab({ gBrowser, url: URL }, async function(
+    browser
+  ) {
+    // At this point, we haven't set gHistoryMaxSize to 0, and it is still 50 (default value).
+    await ContentTask.spawn(browser, null, () => {
+      var sh = content.window.docShell.QueryInterface(Ci.nsIWebNavigation)
+        .sessionHistory.legacySHistory;
+      is(
+        sh.count,
+        1,
+        "We should have entry in session history because we haven't changed gHistoryMaxSize to be 0 yet"
+      );
+      is(
+        sh.index,
+        0,
+        "Shistory's current index should be 0 because we haven't purged history yet"
+      );
+    });
+
+    var loadPromise = BrowserTestUtils.browserLoaded(browser, false, URL2);
+    // If we set the pref at the beginning of this page, then when we launch a child process
+    // to navigate to URL in Step 1, because of
+    // https://searchfox.org/mozilla-central/rev/e7c61f4a68b974d5fecd216dc7407b631a24eb8f/docshell/shistory/nsSHistory.cpp#308-312
+    // this pref will be set to the default value (currently 50). Setting this pref after the child process launches
+    // is a robust way to make sure it stays 0
+    await SpecialPowers.pushPrefEnv({
+      set: [["browser.sessionhistory.max_entries", 0]],
+    });
+    // 2. Navigate to URL2
+    // We are navigating to a page with the same origin so that we will stay in the same process
+    BrowserTestUtils.loadURI(browser, URL2);
+    await loadPromise;
+
+    // 3. Reload the browser with specific flags so that we end up here
+    // https://searchfox.org/mozilla-central/rev/e7c61f4a68b974d5fecd216dc7407b631a24eb8f/docshell/base/nsDocShell.cpp#10795
+    var promise = BrowserTestUtils.browserLoaded(browser);
+    browser.reloadWithFlags(Ci.nsIWebNavigation.LOAD_FLAGS_BYPASS_CACHE);
+    await promise;
+
+    await ContentTask.spawn(browser, null, () => {
+      var sh = content.window.docShell.QueryInterface(Ci.nsIWebNavigation)
+        .sessionHistory.legacySHistory;
+      is(sh.count, 0, "We should not save any entries in session history");
+      is(sh.index, -1);
+      is(sh.requestedIndex, -1);
+    });
+  });
+});