diff --git a/xpcom/io/nsLocalFileWin.cpp b/xpcom/io/nsLocalFileWin.cpp
index 0b9b8f8ded..0aa430d9dd 100644
--- a/xpcom/io/nsLocalFileWin.cpp
+++ b/xpcom/io/nsLocalFileWin.cpp
@@ -3042,6 +3042,7 @@ nsLocalFile::IsExecutable(bool* aResult)
       "jar",         // java application bundle
       "js",
       "jse",
+      "library-ms",  // Windows library files shell extension
       "lnk",
       "mad",         // Access Module Shortcut
       "maf",         // Access