diff --git a/chrome/content/zotero/xpcom/utilities_internal.js b/chrome/content/zotero/xpcom/utilities_internal.js
index a7ac0bbdd9..fff3cd4aea 100644
--- a/chrome/content/zotero/xpcom/utilities_internal.js
+++ b/chrome/content/zotero/xpcom/utilities_internal.js
@@ -1164,6 +1164,29 @@ Zotero.Utilities.Internal = {
 	},
 	
 	
+	/**
+	 * Get the next available numbered name that matches a base name, for use when duplicating
+	 *
+	 * - Given 'Foo' and ['Foo'], returns 'Foo (1)'.
+	 * - Given 'Foo (1)' and ['Foo', 'Foo (1)'], returns 'Foo (2)'
+	 */
+	getNextName: function (name, existingNames) {
+		// Trim '(1)', etc.
+		var matches = name.match(/^(.+) \(\d+\)$/);
+		if (matches) {
+			name = matches[1].trim();
+		}
+		var highest = 0;
+		for (let existingName of existingNames) {
+			let matches = existingName.match(/ \((\d+)\)$/);
+			if (matches && matches[1] > highest) {
+				highest = matches[1];
+			}
+		}
+		return name + ' (' + ++highest + ')';
+	},
+	
+	
 	buildLibraryMenu: function (menulist, libraries, selectedLibraryID) {
 		var menupopup = menulist.firstChild;
 		while (menupopup.hasChildNodes()) {
diff --git a/test/tests/utilities_internalTest.js b/test/tests/utilities_internalTest.js
index 20c36cfade..514c3f060c 100644
--- a/test/tests/utilities_internalTest.js
+++ b/test/tests/utilities_internalTest.js
@@ -200,4 +200,16 @@ describe("Zotero.Utilities.Internal", function () {
 			assert.propertyVal(identifiers[3], "arXiv", "math.GT/0309135");
 		});
 	});
+	
+	describe("#getNextName()", function () {
+		it("should get the next available numbered name", function () {
+			var existing = ['Name (1)', 'Name (3)'];
+			assert.equal(Zotero.Utilities.Internal.getNextName('Name', existing), 'Name (4)');
+		});
+		
+		it("should return 'Name (1)' if no numbered names", function () {
+			var existing = ['Name'];
+			assert.equal(Zotero.Utilities.Internal.getNextName('Name', existing), 'Name (1)');
+		});
+	});
 })