diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 77544f9e9f..0deeb162bd 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -84,7 +84,7 @@ jobs:
       with:
           python-version: '3.8'
     - name: Install Requirements
-      run: pip install pyinstaller mutagen
+      run: pip install pyinstaller mutagen Crypto
     - name: Bump version
       id: bump_version
       run: python devscripts/update-version.py
@@ -122,7 +122,7 @@ jobs:
           python-version: '3.4.4'
           architecture: 'x86'
     - name: Install Requirements for 32 Bit
-      run: pip install pyinstaller==3.5 mutagen
+      run: pip install pyinstaller==3.5 mutagen Crypto
     - name: Bump version
       id: bump_version
       run: python devscripts/update-version.py
diff --git a/README.md b/README.md
index bf52cf84ac..6f57325e04 100644
--- a/README.md
+++ b/README.md
@@ -102,9 +102,9 @@ You can install yt-dlp using one of the following methods:
 ### COMPILE
 
 **For Windows**:
-To build the Windows executable, you must have pyinstaller (and optionally mutagen for embedding thumbnail in opus/ogg files)
+To build the Windows executable, you must have pyinstaller (and optionally mutagen and Crypto)
 
-    python -m pip install --upgrade pyinstaller mutagen
+    python -m pip install --upgrade pyinstaller mutagen Crypto
 
 Once you have all the necessary dependancies installed, just run `py devscripts\pyinst.py`. The executable will be built for the same architecture (32/64 bit) as the python used to build it. It is strongly reccomended to use python3 although python2.6+ is supported.
 
diff --git a/devscripts/pyinst.py b/devscripts/pyinst.py
index 49a055af30..b663d4b2ee 100644
--- a/devscripts/pyinst.py
+++ b/devscripts/pyinst.py
@@ -73,6 +73,7 @@ PyInstaller.__main__.run([
     '--exclude-module=test',
     '--exclude-module=ytdlp_plugins',
     '--hidden-import=mutagen',
+    '--hidden-import=Crypto',
     'youtube_dlc/__main__.py',
 ])
 SetVersion('dist/youtube-dlc%s.exe' % _x86, VERSION_FILE)
diff --git a/requirements.txt b/requirements.txt
index 26ced3f58c..1e880eb514 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1,2 @@
 mutagen
+Crypto
diff --git a/setup.py b/setup.py
index c1e2ec727c..383ad370e6 100644
--- a/setup.py
+++ b/setup.py
@@ -20,7 +20,7 @@ LONG_DESCRIPTION = '\n\n'.join((
     '**PS**: Many links in this document will not work since this is a copy of the README.md from Github',
     open("README.md", "r", encoding="utf-8").read()))
 
-REQUIREMENTS = ['mutagen']
+REQUIREMENTS = ['mutagen', 'Crypto']
 
 
 if len(sys.argv) >= 2 and sys.argv[1] == 'py2exe':
diff --git a/youtube_dlc/postprocessor/embedthumbnail.py b/youtube_dlc/postprocessor/embedthumbnail.py
index da6b6797f5..a54db77f0a 100644
--- a/youtube_dlc/postprocessor/embedthumbnail.py
+++ b/youtube_dlc/postprocessor/embedthumbnail.py
@@ -10,9 +10,9 @@ import base64
 
 try:
     import mutagen
-    _has_mutagen = True
+    has_mutagen = True
 except ImportError:
-    _has_mutagen = False
+    has_mutagen = False
 
 from .ffmpeg import FFmpegPostProcessor
 
@@ -153,7 +153,7 @@ class EmbedThumbnailPP(FFmpegPostProcessor):
                     success = False
 
         elif info['ext'] in ['ogg', 'opus']:
-            if not _has_mutagen:
+            if not has_mutagen:
                 raise EmbedThumbnailPPError('module mutagen was not found. Please install using `python -m pip install mutagen`')
             self.to_screen('Adding thumbnail to "%s"' % filename)