diff --git a/compose/cli/docker_client.py b/compose/cli/docker_client.py
index d4cdc96e8..4553eee86 100644
--- a/compose/cli/docker_client.py
+++ b/compose/cli/docker_client.py
@@ -31,7 +31,7 @@ def default_cert_path():
 
 def make_context(host, options, environment):
     tls = tls_config_from_options(options, environment)
-    ctx = Context("compose", host=host)
+    ctx = Context("compose", host=host, tls=tls.verify if tls else False)
     if tls:
         ctx.set_endpoint("docker", host, tls, skip_tls_verify=not tls.verify)
     return ctx
@@ -138,7 +138,7 @@ def docker_client(environment, version=None, context=None, tls_version=None):
         tls = kwargs.get("tls", None)
         verify = False if not tls else tls.verify
         if host:
-            context = Context("compose", host=host)
+            context = Context("compose", host=host, tls=verify)
         else:
             context = ContextAPI.get_current_context()
         if tls:
diff --git a/compose/cli/main.py b/compose/cli/main.py
index e226a6008..250d06c90 100644
--- a/compose/cli/main.py
+++ b/compose/cli/main.py
@@ -1080,7 +1080,7 @@ class TopLevelCommand(object):
                 log.error(
                     "The image for the service you're trying to recreate has been removed. "
                     "If you continue, volume data could be lost. Consider backing up your data "
-                    "before continuing.\n".format(e.explanation)
+                    "before continuing.\n"
                 )
                 res = yesno("Continue with the new image? [yN]", False)
                 if res is None or not res:
diff --git a/compose/service.py b/compose/service.py
index 92b2b3329..95a87d210 100644
--- a/compose/service.py
+++ b/compose/service.py
@@ -1157,7 +1157,7 @@ class Service(object):
         container_name = build_container_name(
             self.project, service_name, number, slug,
         )
-        ext_links_origins = [l.split(':')[0] for l in self.options.get('external_links', [])]
+        ext_links_origins = [link.split(':')[0] for link in self.options.get('external_links', [])]
         if container_name in ext_links_origins:
             raise DependencyError(
                 'Service {0} has a self-referential external link: {1}'.format(
diff --git a/requirements.txt b/requirements.txt
index 1845798b0..3c86344d9 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,7 +5,7 @@ certifi==2020.4.5.1
 chardet==3.0.4
 colorama==0.4.3; sys_platform == 'win32'
 distro==1.5.0
-docker==4.2.0
+docker==4.2.1
 docker-pycreds==0.4.0
 dockerpty==0.4.1
 docopt==0.6.2