diff --git a/atom/common/asar/archive.cc b/atom/common/asar/archive.cc
index ab93e301b1ab..ebb80cc2c485 100644
--- a/atom/common/asar/archive.cc
+++ b/atom/common/asar/archive.cc
@@ -272,7 +272,8 @@ bool Archive::CopyFileOut(const base::FilePath& path, base::FilePath* out) {
   }
 
   scoped_ptr<ScopedTemporaryFile> temp_file(new ScopedTemporaryFile);
-  if (!temp_file->InitFromFile(&file_, info.offset, info.size))
+  base::FilePath::StringType ext = path.Extension();
+  if (!temp_file->InitFromFile(&file_, ext, info.offset, info.size))
     return false;
 
 #if defined(OS_POSIX)
diff --git a/atom/common/asar/scoped_temporary_file.cc b/atom/common/asar/scoped_temporary_file.cc
index 6fccc9434fdb..2cc51991e185 100644
--- a/atom/common/asar/scoped_temporary_file.cc
+++ b/atom/common/asar/scoped_temporary_file.cc
@@ -28,20 +28,28 @@ ScopedTemporaryFile::~ScopedTemporaryFile() {
   }
 }
 
-bool ScopedTemporaryFile::Init() {
+bool ScopedTemporaryFile::Init(const base::FilePath::StringType ext) {
   if (!path_.empty())
     return true;
 
   base::ThreadRestrictions::ScopedAllowIO allow_io;
-  return base::CreateTemporaryFile(&path_);
+
+  base::FilePath temporaryPath_;
+  if (!base::CreateTemporaryFile(&temporaryPath_)) {
+    return false;
+  }
+
+  path_ = temporaryPath_.AddExtension(ext);
+  return base::Move(temporaryPath_, path_);
 }
 
 bool ScopedTemporaryFile::InitFromFile(base::File* src,
+                                       const base::FilePath::StringType ext,
                                        uint64 offset, uint64 size) {
   if (!src->IsValid())
     return false;
 
-  if (!Init())
+  if (!Init(ext))
     return false;
 
   std::vector<char> buf(size);
diff --git a/atom/common/asar/scoped_temporary_file.h b/atom/common/asar/scoped_temporary_file.h
index ffaee22e514e..c0804a4e6e5f 100644
--- a/atom/common/asar/scoped_temporary_file.h
+++ b/atom/common/asar/scoped_temporary_file.h
@@ -22,11 +22,13 @@ class ScopedTemporaryFile {
   ScopedTemporaryFile();
   virtual ~ScopedTemporaryFile();
 
-  // Init an empty temporary file.
-  bool Init();
+  // Init an empty temporary file with a certain extension.
+  bool Init(const base::FilePath::StringType ext);
 
   // Init an temporary file and fill it with content of |path|.
-  bool InitFromFile(base::File* src, uint64 offset, uint64 size);
+  bool InitFromFile(base::File* src,
+                    const base::FilePath::StringType ext,
+                    uint64 offset, uint64 size);
 
   base::FilePath path() const { return path_; }