diff --git a/chrome/content/zotero/preferences/preferences.js b/chrome/content/zotero/preferences/preferences.js
index a1e8857d07..f08f363b01 100644
--- a/chrome/content/zotero/preferences/preferences.js
+++ b/chrome/content/zotero/preferences/preferences.js
@@ -1914,7 +1914,7 @@ function handleShowInPreferenceChange() {
 /**
  * Opens a URI in the basic viewer in Standalone, or a new window in Firefox
  */
-function openInViewer(uri) {
+function openInViewer(uri, newTab) {
 	var wm = Components.classes["@mozilla.org/appshell/window-mediator;1"]
 		.getService(Components.interfaces.nsIWindowMediator);
 	const features = "menubar=yes,toolbar=no,location=no,scrollbars,centerscreen,resizable";
@@ -1930,7 +1930,11 @@ function openInViewer(uri) {
 	} else {
 		var win = wm.getMostRecentWindow("navigator:browser");
 		if(win) {
-			win.open(uri, null, features);
+			if(newTab) {
+				win.gBrowser.selectedTab = win.gBrowser.addTab(uri);
+			} else {
+				win.open(uri, null, features);
+			}
 		}
 		else {
 			var ww = Components.classes["@mozilla.org/embedcomp/window-watcher;1"]
diff --git a/chrome/content/zotero/preferences/preferences.xul b/chrome/content/zotero/preferences/preferences.xul
index d73f0ad6dd..2058aca637 100644
--- a/chrome/content/zotero/preferences/preferences.xul
+++ b/chrome/content/zotero/preferences/preferences.xul
@@ -800,9 +800,9 @@ To add a new preference:
 		<groupbox>
 			<caption label="&zotero.preferences.miscellaneous;"/>
 			<hbox align="center">
-				<button id="openAboutConfig" label="&zotero.preferences.openAboutConfig;" oncommand="openInViewer('about:config', '')"/>
-				<button id="openCSLEdit" label="&zotero.preferences.openCSLEdit;" oncommand="openInViewer('chrome://zotero/content/tools/csledit.xul', '')"/>
-				<button id="openCSLPreview" label="&zotero.preferences.openCSLPreview;" oncommand="openInViewer('chrome://zotero/content/tools/cslpreview.xul', '')"/>
+				<button id="openAboutConfig" label="&zotero.preferences.openAboutConfig;" oncommand="openInViewer('about:config')"/>
+				<button id="openCSLEdit" label="&zotero.preferences.openCSLEdit;" oncommand="openInViewer('chrome://zotero/content/tools/csledit.xul', true)"/>
+				<button id="openCSLPreview" label="&zotero.preferences.openCSLPreview;" oncommand="openInViewer('chrome://zotero/content/tools/cslpreview.xul', true)"/>
 			</hbox>
 		</groupbox>