--- a/toolkit/components/printing/content/print.html
+++ b/toolkit/components/printing/content/print.html
@@ -180,21 +180,22 @@
               </select>
             </section>
 
             <section id="margins" class="section-block">
               <div id="margins-select" is="margins-select" class="margins-select row"></div>
             </section>
 
             <section id="two-sided-printing" class="section-block">
-              <label class="block-label" data-l10n-id="printui-two-sided-printing"></label>
-              <div class="row cols-2">
-                <input is="setting-checkbox" id="duplex-enabled" data-setting-name="printDuplex">
-                <label for="duplex-enabled" data-l10n-id="printui-duplex-checkbox"></label>
-              </div>
+              <label class="block-label" for="duplex-select" data-l10n-id="printui-two-sided-printing"></label>
+              <select is="setting-select" id="duplex-select" name="duplex-type" class="row" data-setting-name="printDuplex">
+                <option value="off" data-l10n-id="printui-two-sided-printing-off" selected></option>
+                <option value="side-edge" data-l10n-id="printui-two-sided-printing-side-edge"></option>
+                <option value="top-edge" data-l10n-id="printui-two-sided-printing-top-edge"></option>
+              </select>
             </section>
 
             <section id="more-settings-options" class="section-block">
               <label class="block-label" data-l10n-id="printui-options"></label>
               <div id="headers-footers" class="row cols-2">
                 <input is="setting-checkbox" id="headers-footers-enabled" data-setting-name="printFootersHeaders">
                 <label for="headers-footers-enabled" data-l10n-id="printui-headers-footers-checkbox"></label>
               </div>

--- a/toolkit/components/printing/content/print.js
+++ b/toolkit/components/printing/content/print.js
@@ -1327,18 +1327,27 @@ var PrintSettingsViewProxy = {
               value: paper.id,
             };
           });
 
       case "supportsDuplex":
         return this.availablePrinters[target.printerName].supportsDuplex;
 
       case "printDuplex":
-        return target.duplex;
-
+        switch (target.duplex) {
+          case Ci.nsIPrintSettings.kDuplexNone:
+            break;
+          case Ci.nsIPrintSettings.kDuplexFlipOnSideEdge:
+            return "side-edge";
+          case Ci.nsIPrintSettings.kDuplexFlipOnTopEdge:
+            return "top-edge";
+          default:
+            logger.warn("Unexpected duplex value: ", target.duplex);
+        }
+        return "off";
       case "printBackgrounds":
         return target.printBGImages || target.printBGColors;
 
       case "printFootersHeaders":
         // if any of the footer and headers settings have a non-empty string value
         // we consider that "enabled"
         return Object.keys(this.headerFooterSettingsPrefs).some(
           name => !!target[name]
@@ -1415,21 +1424,34 @@ var PrintSettingsViewProxy = {
         // Can't set printerName, settings objects belong to a specific printer.
         break;
 
       case "printBackgrounds":
         target.printBGImages = value;
         target.printBGColors = value;
         break;
 
-      case "printDuplex":
-        target.duplex = value
-          ? Ci.nsIPrintSettings.kDuplexFlipOnSideEdge
-          : Ci.nsIPrintSettings.kDuplexNone;
+      case "printDuplex": {
+        let duplex = (function() {
+          switch (value) {
+            case "off":
+              break;
+            case "side-edge":
+              return Ci.nsIPrintSettings.kDuplexFlipOnSideEdge;
+            case "top-edge":
+              return Ci.nsIPrintSettings.kDuplexFlipOnTopEdge;
+            default:
+              logger.warn("Unexpected duplex name: ", value);
+          }
+          return Ci.nsIPrintSettings.kDuplexNone;
+        })();
+
+        target.duplex = duplex;
         break;
+      }
 
       case "printFootersHeaders":
         // To disable header & footers, set them all to empty.
         // To enable, restore default values for each of the header & footer settings.
         for (let [settingName, defaultValue] of Object.entries(
           this.defaultHeadersAndFooterValues
         )) {
           target[settingName] = value ? defaultValue : "";

--- a/toolkit/components/printing/tests/browser_print_duplex.js
+++ b/toolkit/components/printing/tests/browser_print_duplex.js
@@ -1,13 +1,35 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
 "use strict";
 
+function changeToOption(helper, index) {
+  return helper.waitForSettingsEvent(function() {
+    let select = helper.get("duplex-select");
+    select.focus();
+    select.scrollIntoView({ block: "center" });
+
+    EventUtils.sendKey("space", helper.win);
+    let selectedIndex = select.selectedIndex;
+    info(`Looking for ${index} from ${selectedIndex}`);
+    while (selectedIndex != index) {
+      if (index > selectedIndex) {
+        EventUtils.sendKey("down", helper.win);
+        selectedIndex++;
+      } else {
+        EventUtils.sendKey("up", helper.win);
+        selectedIndex--;
+      }
+    }
+    EventUtils.sendKey("return", helper.win);
+  });
+}
+
 add_task(async function testPDFPrinterIsNonDuplex() {
   await PrintHelper.withTestPage(async helper => {
     await helper.startPrint();
     await helper.openMoreSettings();
 
     is(
       helper.settings.printerName,
       "Mozilla Save to PDF",
@@ -49,23 +71,29 @@ add_task(async function testToggleDuplex
       "The two-sided printing section should not be hidden when the printer supports duplex."
     );
 
     helper.assertSettingsMatch({
       orientation: Ci.nsIPrintSettings.kPortraitOrientation,
       duplex: Ci.nsIPrintSettings.kDuplexNone,
     });
 
-    await helper.click(helper.get("duplex-enabled"));
+    await changeToOption(helper, 1);
     helper.assertSettingsMatch({
       orientation: Ci.nsIPrintSettings.kPortraitOrientation,
       duplex: Ci.nsIPrintSettings.kDuplexFlipOnSideEdge,
     });
 
-    await helper.click(helper.get("duplex-enabled"));
+    await changeToOption(helper, 2);
+    helper.assertSettingsMatch({
+      orientation: Ci.nsIPrintSettings.kPortraitOrientation,
+      duplex: Ci.nsIPrintSettings.kDuplexFlipOnTopEdge,
+    });
+
+    await changeToOption(helper, 0);
     helper.assertSettingsMatch({
       orientation: Ci.nsIPrintSettings.kPortraitOrientation,
       duplex: Ci.nsIPrintSettings.kDuplexNone,
     });
 
     await helper.closeDialog();
   });
 });
@@ -100,24 +128,30 @@ add_task(async function testToggleDuplex
 
     await helper.dispatchSettingsChange({ orientation: 1 });
     await helper.awaitAnimationFrame();
     await helper.assertSettingsMatch({
       orientation: Ci.nsIPrintSettings.kLandscapeOrientation,
       duplex: Ci.nsIPrintSettings.kDuplexNone,
     });
 
-    await helper.click(helper.get("duplex-enabled"));
-    await helper.assertSettingsMatch({
+    await changeToOption(helper, 1);
+    helper.assertSettingsMatch({
       orientation: Ci.nsIPrintSettings.kLandscapeOrientation,
       duplex: Ci.nsIPrintSettings.kDuplexFlipOnSideEdge,
     });
 
-    await helper.click(helper.get("duplex-enabled"));
-    await helper.assertSettingsMatch({
+    await changeToOption(helper, 2);
+    helper.assertSettingsMatch({
+      orientation: Ci.nsIPrintSettings.kLandscapeOrientation,
+      duplex: Ci.nsIPrintSettings.kDuplexFlipOnTopEdge,
+    });
+
+    await changeToOption(helper, 0);
+    helper.assertSettingsMatch({
       orientation: Ci.nsIPrintSettings.kLandscapeOrientation,
       duplex: Ci.nsIPrintSettings.kDuplexNone,
     });
 
     await helper.closeDialog();
   });
 });
 
@@ -144,17 +178,18 @@ add_task(async function testSwitchOrient
       "The two-sided printing section should not be hidden when the printer supports duplex."
     );
 
     await helper.assertSettingsMatch({
       orientation: Ci.nsIPrintSettings.kPortraitOrientation,
       duplex: Ci.nsIPrintSettings.kDuplexNone,
     });
 
-    await helper.click(helper.get("duplex-enabled"));
+    await changeToOption(helper, 1);
+
     await helper.assertSettingsMatch({
       orientation: Ci.nsIPrintSettings.kPortraitOrientation,
       duplex: Ci.nsIPrintSettings.kDuplexFlipOnSideEdge,
     });
 
     await helper.dispatchSettingsChange({ orientation: 1 });
     await helper.awaitAnimationFrame();
     await helper.assertSettingsMatch({

--- a/toolkit/locales/en-US/toolkit/printing/printUI.ftl
+++ b/toolkit/locales/en-US/toolkit/printing/printUI.ftl
@@ -42,17 +42,21 @@ printui-paper-size-label = Paper size
 # Section title (noun) for the print scaling options
 printui-scale = Scale
 printui-scale-fit-to-page-width = Fit to page width
 # Label for input control where user can set the scale percentage
 printui-scale-pcent = Scale
 
 # Section title (noun) for the two-sided print options
 printui-two-sided-printing = Two-sided printing
-printui-duplex-checkbox = Print on both sides
+printui-two-sided-printing-off = Off
+# Flip the page on the side (like a book).
+printui-two-sided-printing-side-edge = Flip on side edge
+# Flip the page on the top (like a vertical calendar).
+printui-two-sided-printing-top-edge = Flip on top edge
 
 # Section title for miscellaneous print options
 printui-options = Options
 printui-headers-footers-checkbox = Print headers and footers
 printui-backgrounds-checkbox = Print backgrounds
 printui-selection-checkbox = Print selection only
 
 printui-color-mode-label = Color mode