diff --git a/index.js b/index.js
index c680b84..b1a275d 100644
--- a/index.js
+++ b/index.js
@@ -441,7 +441,9 @@ MochaJUnitReporter.prototype.getXml = function(testsuites) {
 
       _suiteAttr.skipped += Number('skipped' in lastNode);
       _suiteAttr.failures += Number('failure' in lastNode);
-      testcase.testcase[0]._attr.time = testcase.testcase[0]._attr.time.toFixed(3);
+      if (typeof testcase.testcase[0]._attr.time === 'number') {
+        testcase.testcase[0]._attr.time = testcase.testcase[0]._attr.time.toFixed(3);
+      }
     });
 
     if (antMode) {
diff --git a/test/mocha-junit-reporter-spec.js b/test/mocha-junit-reporter-spec.js
index 6663582..d14a7ef 100644
--- a/test/mocha-junit-reporter-spec.js
+++ b/test/mocha-junit-reporter-spec.js
@@ -19,6 +19,7 @@ var FakeTimer = require('@sinonjs/fake-timers');
 var xmllint = require('xmllint');
 var chaiXML = require('chai-xml');
 var mockXml = require('./mock-results');
+var mockJunitSuites = require('./mock-junit-suites');
 var testConsole = require('test-console');
 
 var debug = require('debug')('mocha-junit-reporter:tests');
@@ -232,6 +233,12 @@ describe('mocha-junit-reporter', function() {
     });
   });
 
+  it('can handle getXml being called twice', function() {
+    var reporter = createReporter({mochaFile: 'test/output/mocha.xml'});
+    var testsuites = mockJunitSuites.withStringTimes();
+    reporter.getXml(testsuites);
+  });
+
   it('respects `process.env.MOCHA_FILE`', function(done) {
     process.env.MOCHA_FILE = 'test/output/results.xml';
     var reporter = createReporter();
diff --git a/test/mock-junit-suites.js b/test/mock-junit-suites.js
new file mode 100644
index 0000000..59cf218
--- /dev/null
+++ b/test/mock-junit-suites.js
@@ -0,0 +1,41 @@
+'use strict';
+
+module.exports = {
+  withStringTimes: function() {
+    return [
+      {
+        testsuite: [
+          {
+            _attr: {
+              name: "Foo Bar",
+              timestamp: "1970-01-01T00:00:00",
+              tests: "3",
+              failures: "2",
+              time: "100.001"
+            }
+          },
+          {
+            testcase: [
+              {
+                _attr: {
+                  name: "Foo Bar can narfle the garthog",
+                  classname: "can narfle the garthog",
+                  time: "2.002"
+                }
+              },
+              {
+                failure: {
+                  _attr: {
+                      message: "expected garthog to be dead",
+                      type: "Error"
+                  },
+                  _cdata: "this is where the stack would be"
+                }
+              }
+            ]
+          },
+        ]
+      },
+    ];
+  }
+};