diff --git a/tools/test-locked-requirements b/tools/test-locked-requirements
index e98b7eb99a..7172f68e2f 100755
--- a/tools/test-locked-requirements
+++ b/tools/test-locked-requirements
@@ -57,8 +57,8 @@ def get_requirements_hash(tmp_dir: str, use_test_lock_files: bool = False) -> st
         lock_files_path = tmp_dir
     reqs_files.extend(sorted(glob.glob(os.path.join(lock_files_path, "*.txt"))))
     for file_path in reqs_files:
-        with open(file_path) as fp:
-            sha1.update(fp.read().encode("utf-8"))
+        with open(file_path, 'rb') as fp:
+            sha1.update(fp.read())
     return sha1.hexdigest()
 
 def may_be_setup_cache() -> None:
diff --git a/tools/test-run-dev b/tools/test-run-dev
index f7d882373f..7c1f17296d 100755
--- a/tools/test-run-dev
+++ b/tools/test-run-dev
@@ -16,11 +16,11 @@ def start_server(logfile_name: str) -> Tuple[bool, str]:
     failure = True
     key = "Quit the server with CTRL-C."
     datalog = []
-    with open(logfile_name, 'rb', buffering=0) as logfile:
+    with open(logfile_name, 'r', buffering=0) as logfile:
         for i in range(200):
             time.sleep(0.5)
             print(f"{i}. Polling run-dev...")
-            new_data = logfile.read().decode()
+            new_data = logfile.read()
             if new_data:
                 datalog.append(new_data)
 
diff --git a/tools/zulip-export/zulip-export b/tools/zulip-export/zulip-export
index 98dbf16ecf..fcc1b2e6de 100755
--- a/tools/zulip-export/zulip-export
+++ b/tools/zulip-export/zulip-export
@@ -78,7 +78,7 @@ for msg in result['messages']:
     messages.append(msg)
 
 filename = f"zulip-{options.stream}.json"
-with open(filename, 'wb') as f:
-    f.write(json.dumps(messages, indent=0, sort_keys=False).encode('utf-8'))
+with open(filename, 'w') as f:
+    json.dump(messages, f, indent=0, sort_keys=False)
 print(f"{len(messages)} messages exported to {filename}")
 sys.exit(0)
diff --git a/zerver/worker/queue_processors.py b/zerver/worker/queue_processors.py
index 4013755640..902254df34 100644
--- a/zerver/worker/queue_processors.py
+++ b/zerver/worker/queue_processors.py
@@ -329,8 +329,8 @@ class QueueProcessingWorker(ABC):
         line = f'{time.asctime()}\t{orjson.dumps(events).decode()}\n'
         lock_fn = fn + '.lock'
         with lockfile(lock_fn):
-            with open(fn, 'ab') as f:
-                f.write(line.encode('utf-8'))
+            with open(fn, 'a') as f:
+                f.write(line)
         check_and_send_restart_signal()
 
     def setup(self) -> None: