diff --git a/NEWS b/NEWS
index 15677860..cb1ab7d0 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,7 @@
+# 1.7.1
+
+* Handle numbering level definitions without an explicit format.
+
 # 1.7.0
 
 * Support attributes in HTML paths in style mappings.
diff --git a/lib/docx/numbering-xml.js b/lib/docx/numbering-xml.js
index 832e414a..7e368ac6 100644
--- a/lib/docx/numbering-xml.js
+++ b/lib/docx/numbering-xml.js
@@ -66,7 +66,7 @@ function readAbstractNum(element) {
     var levels = {};
     element.getElementsByTagName("w:lvl").forEach(function(levelElement) {
         var levelIndex = levelElement.attributes["w:ilvl"];
-        var numFmt = levelElement.first("w:numFmt").attributes["w:val"];
+        var numFmt = levelElement.firstOrEmpty("w:numFmt").attributes["w:val"];
         var paragraphStyleId = levelElement.firstOrEmpty("w:pStyle").attributes["w:val"];
 
         levels[levelIndex] = {
diff --git a/test/docx/numbering-xml.tests.js b/test/docx/numbering-xml.tests.js
index 1a20ab0c..a648349f 100644
--- a/test/docx/numbering-xml.tests.js
+++ b/test/docx/numbering-xml.tests.js
@@ -45,6 +45,23 @@ test('w:num element referencing non-existent w:abstractNumId is ignored', functi
     duck.assertThat(numbering.findLevel("47", "0"), duck.equalTo(null));
 });
 
+test('when level is missing w:numFmt then level is ordered', function() {
+    var numbering = readNumberingXml(
+        new XmlElement("w:numbering", {}, [
+            new XmlElement("w:abstractNum", {"w:abstractNumId": "42"}, [
+                new XmlElement("w:lvl", {"w:ilvl": "0"})
+            ]),
+            new XmlElement("w:num", {"w:numId": "47"}, [
+                new XmlElement("w:abstractNumId", {"w:val": "42"})
+            ])
+        ]),
+        {styles: stylesReader.defaultStyles}
+    );
+    duck.assertThat(numbering.findLevel("47", "0"), duck.hasProperties({
+        isOrdered: true
+    }));
+});
+
 
 test('when w:abstractNum has w:numStyleLink then style is used to find w:num', function() {
     var numbering = readNumberingXml(