--- a/toolkit/components/passwordmgr/nsLoginManagerPrompter.js
+++ b/toolkit/components/passwordmgr/nsLoginManagerPrompter.js
@@ -831,16 +831,17 @@ LoginManagerPrompter.prototype = {
                                   });
 
     let chromeDoc = browser.ownerDocument;
 
     let currentNotification;
 
     let updateButtonStatus = (element) => {
       let mainActionButton = element.button;
+      this.mainActionButton = mainActionButton;
       // Disable the main button inside the menu-button if the password field is empty.
       if (login.password.length == 0) {
         mainActionButton.setAttribute("disabled", true);
         chromeDoc.getElementById("password-notification-password")
                  .classList.add("popup-notification-invalid-input");
       } else {
         mainActionButton.removeAttribute("disabled");
         chromeDoc.getElementById("password-notification-password")
@@ -900,16 +901,22 @@ LoginManagerPrompter.prototype = {
         chromeDoc.getElementById("password-notification-password").value;
     };
 
     let onInput = () => {
       readDataFromUI();
       updateButtonLabel();
     };
 
+    let handleSubmit = (e) => {
+      if (e.keyCode == 13) {
+        this.mainActionButton.click();
+      }
+    };
+
     let onVisibilityToggle = (commandEvent) => {
       let passwordField = chromeDoc.getElementById("password-notification-password");
       // Gets the caret position before changing the type of the textbox
       let selectionStart = passwordField.selectionStart;
       let selectionEnd = passwordField.selectionEnd;
       passwordField.setAttribute("type", commandEvent.target.checked ? "" : "password");
       if (!passwordField.hasAttribute("focused")) {
         return;
@@ -1022,16 +1029,18 @@ LoginManagerPrompter.prototype = {
               chromeDoc.getElementById("password-notification-password")
                        .removeAttribute("focused");
               chromeDoc.getElementById("password-notification-username")
                        .removeAttribute("focused");
               chromeDoc.getElementById("password-notification-username")
                        .addEventListener("input", onInput);
               chromeDoc.getElementById("password-notification-password")
                        .addEventListener("input", onInput);
+              chromeDoc.getElementById("password-notification-password")
+                       .addEventListener("keyup", handleSubmit);
               let toggleBtn = chromeDoc.getElementById("password-notification-visibilityToggle");
 
               if (Services.prefs.getBoolPref("signon.rememberSignons.visibilityToggle")) {
                 toggleBtn.addEventListener("command", onVisibilityToggle);
                 toggleBtn.setAttribute("label", togglePasswordLabel);
                 toggleBtn.setAttribute("accesskey", togglePasswordAccessKey);
                 toggleBtn.setAttribute("hidden", LoginHelper.isMasterPasswordSet());
               }
@@ -1050,16 +1059,18 @@ LoginManagerPrompter.prototype = {
             case "removed":
               currentNotification = null;
               chromeDoc.getElementById("password-notification-username")
                        .removeEventListener("input", onInput);
               chromeDoc.getElementById("password-notification-password")
                        .removeEventListener("input", onInput);
               chromeDoc.getElementById("password-notification-visibilityToggle")
                        .removeEventListener("command", onVisibilityToggle);
+              chromeDoc.getElementById("password-notification-password")
+                       .removeEventListener("keyup", handleSubmit);
               break;
           }
           return false;
         },
       }
     );
   },
 

--- a/toolkit/components/passwordmgr/test/browser/browser_capture_doorhanger.js
+++ b/toolkit/components/passwordmgr/test/browser/browser_capture_doorhanger.js
@@ -568,16 +568,59 @@ add_task(async function test_recipeCaptu
   let login = logins[0].QueryInterface(Ci.nsILoginMetaInfo);
   is(login.username, "notifyu1", "Check the username unchanged");
   is(login.password, "notifyp1", "Check the password unchanged");
   is(login.timesUsed, 2, "Check times used incremented");
 
   Services.logins.removeAllLogins();
 });
 
+add_task(async function test_saveUsingEnter() {
+  await testSubmittingLoginForm("subtst_notifications_1.html", async function(fieldValues) {
+    is(fieldValues.username, "notifyu1", "Checking submitted username");
+    is(fieldValues.password, "notifyp1", "Checking submitted password");
+    let notif = getCaptureDoorhanger("password-save");
+    ok(notif, "got notification popup");
+
+    is(Services.logins.getAllLogins().length, 0, "Should not have any logins yet");
+
+    await checkDoorhangerUsernamePassword("notifyu1", "notifyp1");
+    document.getElementById("password-notification-password").focus();
+    await EventUtils.synthesizeKey("KEY_Enter");
+
+  });
+
+  let logins = Services.logins.getAllLogins();
+  is(logins.length, 1, "Should only have 1 login");
+  let login = logins[0].QueryInterface(Ci.nsILoginMetaInfo);
+  is(login.username, "notifyu1", "Check the username used on the new entry");
+  is(login.password, "notifyp1", "Check the password used on the new entry");
+  is(login.timesUsed, 1, "Check times used on new entry");
+
+  info("Make sure Remember took effect and we don't prompt for an existing login");
+  await testSubmittingLoginForm("subtst_notifications_1.html", function(fieldValues) {
+    is(fieldValues.username, "notifyu1", "Checking submitted username");
+    is(fieldValues.password, "notifyp1", "Checking submitted password");
+    let notif = getCaptureDoorhanger("password-save");
+    ok(!notif, "checking for no notification popup");
+  });
+
+  logins = Services.logins.getAllLogins();
+  is(logins.length, 1, "Should only have 1 login");
+  login = logins[0].QueryInterface(Ci.nsILoginMetaInfo);
+  is(login.username, "notifyu1", "Check the username used");
+  is(login.password, "notifyp1", "Check the password used");
+  is(login.timesUsed, 2, "Check times used incremented");
+
+  checkOnlyLoginWasUsedTwice({ justChanged: false });
+
+  // remove that login
+  Services.logins.removeLogin(login1);
+});
+
 add_task(async function test_noShowPasswordOnDismissal() {
   info("Check for no Show Password field when the doorhanger is dismissed");
 
   await testSubmittingLoginForm("subtst_notifications_1.html", async function(fieldValues) {
     info("Opening popup");
     let notif = getCaptureDoorhanger("password-save");
     let { panel } = PopupNotifications;