diff --git a/taglib/mp4/mp4properties.cpp b/taglib/mp4/mp4properties.cpp
index 0ac77342..ba821547 100644
--- a/taglib/mp4/mp4properties.cpp
+++ b/taglib/mp4/mp4properties.cpp
@@ -187,7 +187,7 @@ MP4::Properties::read(File *file, Atoms *atoms)
     length = data.toUInt(24U);
   }
   if(unit > 0 && length > 0)
-    d->length = static_cast<int>(length * 1000.0 / unit);
+    d->length = static_cast<int>(length * 1000.0 / unit + 0.5);
 
   MP4::Atom *atom = trak->find("mdia", "minf", "stbl", "stsd");
   if(!atom) {
diff --git a/tests/test_mp4.cpp b/tests/test_mp4.cpp
index c110a612..58dbae42 100644
--- a/tests/test_mp4.cpp
+++ b/tests/test_mp4.cpp
@@ -40,7 +40,7 @@ public:
     CPPUNIT_ASSERT(f.audioProperties());
     CPPUNIT_ASSERT_EQUAL(3, f.audioProperties()->length());
     CPPUNIT_ASSERT_EQUAL(3, f.audioProperties()->lengthInSeconds());
-    CPPUNIT_ASSERT_EQUAL(3707, f.audioProperties()->lengthInMilliseconds());
+    CPPUNIT_ASSERT_EQUAL(3708, f.audioProperties()->lengthInMilliseconds());
     CPPUNIT_ASSERT_EQUAL(3, f.audioProperties()->bitrate());
     CPPUNIT_ASSERT_EQUAL(2, f.audioProperties()->channels());
     CPPUNIT_ASSERT_EQUAL(44100, f.audioProperties()->sampleRate());