diff --git a/gunicorn/asgi/protocol.py b/gunicorn/asgi/protocol.py
index 9ea2fa35..049280a5 100644
--- a/gunicorn/asgi/protocol.py
+++ b/gunicorn/asgi/protocol.py
@@ -10,7 +10,6 @@ and dispatch to ASGI applications.
 """
 
 import asyncio
-import ssl
 from datetime import datetime
 
 from gunicorn.asgi.unreader import AsyncUnreader
diff --git a/gunicorn/http2/async_connection.py b/gunicorn/http2/async_connection.py
index a40c4ad3..6c90c489 100644
--- a/gunicorn/http2/async_connection.py
+++ b/gunicorn/http2/async_connection.py
@@ -11,7 +11,6 @@ asyncio for non-blocking I/O.
 """
 
 import asyncio
-from io import BytesIO
 
 from .errors import (
     HTTP2Error, HTTP2ProtocolError, HTTP2ConnectionError,
diff --git a/gunicorn/http2/request.py b/gunicorn/http2/request.py
index 9dbdb752..b1c2ac40 100644
--- a/gunicorn/http2/request.py
+++ b/gunicorn/http2/request.py
@@ -10,9 +10,7 @@ Provides a Request-compatible interface for HTTP/2 streams.
 """
 
 from io import BytesIO
-from urllib.parse import unquote, urlparse
 
-from gunicorn.http.body import Body, LengthReader
 from gunicorn.util import split_request_uri
 
 
diff --git a/gunicorn/http2/stream.py b/gunicorn/http2/stream.py
index 223fd441..45ba2776 100644
--- a/gunicorn/http2/stream.py
+++ b/gunicorn/http2/stream.py
@@ -12,7 +12,7 @@ Each HTTP/2 stream represents a single request/response exchange.
 from enum import Enum, auto
 from io import BytesIO
 
-from .errors import HTTP2StreamError, HTTP2StreamClosed
+from .errors import HTTP2StreamError
 
 
 class StreamState(Enum):
diff --git a/gunicorn/workers/gthread.py b/gunicorn/workers/gthread.py
index 994ca0cc..0e3f5e2d 100644
--- a/gunicorn/workers/gthread.py
+++ b/gunicorn/workers/gthread.py
@@ -454,7 +454,7 @@ class ThreadWorker(base.Worker):
         except OSError as e:
             if e.errno not in (errno.EPIPE, errno.ECONNRESET, errno.ENOTCONN):
                 self.log.exception("HTTP/2 socket error")
-        except Exception as e:
+        except Exception:
             self.log.exception("HTTP/2 connection error")
 
         return False