diff --git a/app/logical/media_file.rb b/app/logical/media_file.rb
index 6487f8247..534f91dbb 100644
--- a/app/logical/media_file.rb
+++ b/app/logical/media_file.rb
@@ -56,7 +56,14 @@ class MediaFile
       :swf
     when /\x1a\x45\xdf\xa3/n
       :webm
-    when /\A....ftyp(?:isom|3gp5|mp42|MSNV|avc1)/
+
+    # https://www.ftyps.com
+    # isom (common) - MP4 Base Media v1 [IS0 14496-12:2003]
+    # mp42 (common) - MP4 v2 [ISO 14496-14]
+    # 3gp5 (rare) - 3GPP Media (.3GP) Release 5
+    # avc1 (rare) - MP4 Base w/ AVC ext [ISO 14496-12:2005]
+    # M4V (rare) - Apple iTunes Video (https://en.wikipedia.org/wiki/M4V)
+    when /\A....ftyp(?:isom|3gp5|mp42|avc1|M4V)/
       :mp4
     when /\APK\x03\x04/
       :zip
diff --git a/test/files/test-audio.m4v b/test/files/test-audio.m4v
new file mode 100644
index 000000000..d7cad067a
Binary files /dev/null and b/test/files/test-audio.m4v differ
diff --git a/test/functional/uploads_controller_test.rb b/test/functional/uploads_controller_test.rb
index bbf43c610..b2bba1319 100644
--- a/test/functional/uploads_controller_test.rb
+++ b/test/functional/uploads_controller_test.rb
@@ -261,6 +261,7 @@ class UploadsControllerTest < ActionDispatch::IntegrationTest
         should_upload_successfully("test/files/test-animated-86x52.gif")
         should_upload_successfully("test/files/test-300x300.mp4")
         should_upload_successfully("test/files/test-512x512.webm")
+        should_upload_successfully("test/files/test-audio.m4v")
         # should_upload_successfully("test/files/compressed.swf")
       end
 
diff --git a/test/unit/media_file_test.rb b/test/unit/media_file_test.rb
index 986efca66..c1f4f9866 100644
--- a/test/unit/media_file_test.rb
+++ b/test/unit/media_file_test.rb
@@ -93,6 +93,10 @@ class MediaFileTest < ActiveSupport::TestCase
       assert_equal(:mp4, MediaFile.open("test/files/test-300x300.mp4").file_ext)
     end
 
+    should "determine the correct extension for a m4v file" do
+      assert_equal(:mp4, MediaFile.open("test/files/test-audio.m4v").file_ext)
+    end
+
     should "determine the correct extension for a ugoira file" do
       assert_equal(:zip, MediaFile.open("test/files/ugoira.zip").file_ext)
     end