diff --git a/python_appimage/appimage/__init__.py b/python_appimage/appimage/__init__.py
index eeeee14..f976473 100644
--- a/python_appimage/appimage/__init__.py
+++ b/python_appimage/appimage/__init__.py
@@ -1,6 +1,7 @@
 from .build import build_appimage
-from .relocate import patch_binary, relocate_python, tcltk_env_string
+from .relocate import cert_file_env_string, patch_binary, relocate_python,     \
+                      tcltk_env_string
 
 
-__all__ = ['build_appimage', 'patch_binary', 'relocate_python',
-           'tcltk_env_string']
+__all__ = ['build_appimage', 'cert_file_env_string', 'patch_binary',
+           'relocate_python', 'tcltk_env_string']
diff --git a/python_appimage/appimage/relocate.py b/python_appimage/appimage/relocate.py
index 5331578..cf39ea5 100644
--- a/python_appimage/appimage/relocate.py
+++ b/python_appimage/appimage/relocate.py
@@ -12,7 +12,8 @@ from ..utils.system import ldd, system
 from ..utils.template import copy_template, load_template
 
 
-__all__ = ["patch_binary", "relocate_python", "tcltk_env_string"]
+__all__ = ["cert_file_env_string", "patch_binary", "relocate_python",
+           "tcltk_env_string"]
 
 
 def _copy_template(name, destination, **kwargs):
diff --git a/python_appimage/commands/build/app.py b/python_appimage/commands/build/app.py
index 8c9add9..9c7f591 100644
--- a/python_appimage/commands/build/app.py
+++ b/python_appimage/commands/build/app.py
@@ -7,7 +7,7 @@ import shutil
 import stat
 import struct
 
-from ...appimage import build_appimage, tcltk_env_string
+from ...appimage import build_appimage, cert_file_env_string, tcltk_env_string
 from ...utils.compat import decode
 from ...utils.deps import PREFIX
 from ...utils.fs import copy_file, make_tree, remove_file, remove_tree
@@ -256,9 +256,13 @@ def execute(appdir, name=None, python_version=None, linux_tag=None,
             entrypoint = load_template(entrypoint_path, **dictionary)
             python_pkg = 'AppDir/opt/python{0:}/lib/python{0:}'.format(
                 python_version)
+            cert_file = '/opt/_internal/certs.pem'
+            if not os.path.exists('AppDir' + cert_file):
+                cert_file = None
             dictionary = {'entrypoint': entrypoint,
                           'shebang': shebang,
-                          'tcltk-env': tcltk_env_string(python_pkg)}
+                          'tcltk-env': tcltk_env_string(python_pkg),
+                          'cert-file': cert_file_env_string(cert_file)}
             copy_template(PREFIX + '/data/apprun.sh', 'AppDir/AppRun',
                           **dictionary)