diff --git a/bypy/windows/__main__.py b/bypy/windows/__main__.py
index ecf642975b..3490f16cbc 100644
--- a/bypy/windows/__main__.py
+++ b/bypy/windows/__main__.py
@@ -128,10 +128,10 @@ def freeze(env, ext_dir, incdir):
 
     printf('\tAdding misc binary deps')
 
-    def copybin(x):
-        shutil.copy2(x, env.dll_dir)
+    def copybin(x, dest=env.dll_dir):
+        shutil.copy2(x, dest)
         with contextlib.suppress(FileNotFoundError):
-            shutil.copy2(x + '.manifest', env.dll_dir)
+            shutil.copy2(x + '.manifest', dest)
 
     bindir = os.path.join(PREFIX, 'bin')
     for x in ('pdftohtml', 'pdfinfo', 'pdftoppm', 'pdftotext', 'jpegtran-calibre', 'cjpeg-calibre', 'optipng-calibre', 'cwebp-calibre', 'JXRDecApp-calibre'):
@@ -139,6 +139,10 @@ def freeze(env, ext_dir, incdir):
     for f in glob.glob(os.path.join(bindir, '*.dll')):
         if re.search(r'(easylzma|icutest)', f.lower()) is None:
             copybin(f)
+    ossm = os.path.join(env.dll_dir, 'ossl-modules')
+    os.mkdir(ossm)
+    for f in glob.glob(os.path.join(PREFIX, 'lib', 'ossl-modules', '*.dll')):
+        copybin(f, ossm)
 
     copybin(os.path.join(env.python_base, 'python%s.dll' % env.py_ver.replace('.', '')))
     copybin(os.path.join(env.python_base, 'python%s.dll' % env.py_ver[0]))
diff --git a/bypy/windows/util.c b/bypy/windows/util.c
index 70f2abbe43..db889dd0d2 100644
--- a/bypy/windows/util.c
+++ b/bypy/windows/util.c
@@ -43,6 +43,8 @@ get_app_dirw(void) {
 static void
 get_install_locations(void) {
     get_app_dirw();
+    _snwprintf_s(qt_prefix_dir, MAX_PATH-1, _TRUNCATE, L"%ls\\ossl-modules", interpreter_data.executables_path);
+    _wputenv_s(L"OPENSSL_MODULES", qt_prefix_dir);
     _snwprintf_s(qt_prefix_dir, MAX_PATH-1, _TRUNCATE, L"%ls\\app", interpreter_data.app_dir);
     _wputenv_s(L"CALIBRE_QT_PREFIX", qt_prefix_dir);
 }
diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index 38a9107086..e3d976f5f8 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -1387,7 +1387,7 @@ def sanitize_env_vars():
             'LD_LIBRARY_PATH':'/lib', 'OPENSSL_MODULES': '/lib/ossl-modules',
         }
     elif iswindows:
-        env_vars = {}
+        env_vars = {'OPENSSL_MODULES': None}
     elif ismacos:
         env_vars = {k:None for k in (
                     'FONTCONFIG_FILE FONTCONFIG_PATH SSL_CERT_FILE OPENSSL_ENGINES OPENSSL_MODULES').split()}