diff --git a/toolkit/locales/en-US/chrome/mozapps/downloads/unknownContentType.properties b/toolkit/locales/en-US/chrome/mozapps/downloads/unknownContentType.properties
index c607dcafefd..332fc2e0e2d 100644
--- a/toolkit/locales/en-US/chrome/mozapps/downloads/unknownContentType.properties
+++ b/toolkit/locales/en-US/chrome/mozapps/downloads/unknownContentType.properties
@@ -17,20 +17,3 @@ unknownCancel.label=Cancel
 fileType=%S file
 # LOCALIZATION NOTE (orderedFileSizeWithType): first %S is type, second %S is size, and third %S is unit  
 orderedFileSizeWithType=%1$S (%2$S %3$S)
-
-# LOCALIZATION NOTE (wpsDefaultOS2): OS/2 only, WPS refers to the Workplace Shell and should probably not be translated
-wpsDefaultOS2=WPS Default
-# LOCALIZATION NOTE (classViewerOS2): OS/2 only
-classViewerOS2=Viewer for Class %S
-# LOCALIZATION NOTE (mmImageViewerOS2): OS/2 only, default operation of image files with OS/2 multimedia support installed
-mmImageViewerOS2=Image Viewer
-# LOCALIZATION NOTE (mmAudioPlayerOS2): OS/2 only, default operation of audio files with OS/2 multimedia support installed
-mmAudioPlayerOS2=Audio Player
-# LOCALIZATION NOTE (mmVideoPlayerOS2): OS/2 only, default operation of video files with OS/2 multimedia support installed
-mmVideoPlayerOS2=Video Player
-# LOCALIZATION NOTE (mmMidiPlayerOS2): OS/2 only, default operation of MIDI files with OS/2 multimedia support installed
-mmMidiPlayerOS2=MIDI Player
-# LOCALIZATION NOTE (odZipFolderOS2): OS/2 only, refers to ZipFolder of Object Desktop
-odZipFolderOS2=ZipFolder
-# LOCALIZATION NOTE (odTextViewOS2): OS/2 only, refers to TextView of Object Desktop
-odTextViewOS2=TextView