diff --git a/emmett/__version__.py b/emmett/__version__.py
index fab833f3..b482efeb 100644
--- a/emmett/__version__.py
+++ b/emmett/__version__.py
@@ -1 +1 @@
-__version__ = "2.6.1"
+__version__ = "2.6.2"
diff --git a/emmett/cli.py b/emmett/cli.py
index 0a64d7b6..f54f3c73 100644
--- a/emmett/cli.py
+++ b/emmett/cli.py
@@ -15,6 +15,7 @@
 
 import code
 import os
+import pathlib
 import re
 import sys
 import types
@@ -232,8 +233,18 @@ def main(self, *args, **kwargs):
 @click.option(
     "--loop", type=click.Choice(["auto", "asyncio", "uvloop"]), default="auto", help="Event loop implementation."
 )
-@click.option("--ssl-certfile", type=str, default=None, help="SSL certificate file")
-@click.option("--ssl-keyfile", type=str, default=None, help="SSL key file")
+@click.option(
+    "--ssl-certfile",
+    type=click.Path(exists=True, file_okay=True, dir_okay=False, readable=True, path_type=pathlib.Path),
+    default=None,
+    help="SSL certificate file",
+)
+@click.option(
+    "--ssl-keyfile",
+    type=click.Path(exists=True, file_okay=True, dir_okay=False, readable=True, path_type=pathlib.Path),
+    default=None,
+    help="SSL key file",
+)
 @click.option("--reloader/--no-reloader", is_flag=True, default=True, help="Runs with reloader.")
 @pass_script_info
 def develop_command(info, host, port, interface, loop, ssl_certfile, ssl_keyfile, reloader):
@@ -296,8 +307,18 @@ def develop_command(info, host, port, interface, loop, ssl_certfile, ssl_keyfile
 @click.option("--access-log/--no-access-log", is_flag=True, default=False, help="Enable access log.")
 @click.option("--backlog", type=int, default=2048, help="Maximum number of connections to hold in backlog")
 @click.option("--backpressure", type=int, help="Maximum number of requests to process concurrently (per worker)")
-@click.option("--ssl-certfile", type=str, default=None, help="SSL certificate file")
-@click.option("--ssl-keyfile", type=str, default=None, help="SSL key file")
+@click.option(
+    "--ssl-certfile",
+    type=click.Path(exists=True, file_okay=True, dir_okay=False, readable=True, path_type=pathlib.Path),
+    default=None,
+    help="SSL certificate file",
+)
+@click.option(
+    "--ssl-keyfile",
+    type=click.Path(exists=True, file_okay=True, dir_okay=False, readable=True, path_type=pathlib.Path),
+    default=None,
+    help="SSL key file",
+)
 @pass_script_info
 def serve_command(
     info,
diff --git a/emmett/forms.py b/emmett/forms.py
index bc0edb0e..77e5ee84 100644
--- a/emmett/forms.py
+++ b/emmett/forms.py
@@ -384,8 +384,8 @@ async def _process(self, **kwargs):
             #: handle uploads
             for field in filter(lambda f: f.type == "upload", self.writable_fields):
                 upload = self.files[field.name]
-                del_field = field.name + "__del"
-                if not upload.filename:
+                if not upload:
+                    del_field = field.name + "__del"
                     if self.input_params.get(del_field, False):
                         self.params[field.name] = self.table[field.name].default or ""
                         # TODO: do we want to physically delete file?
diff --git a/emmett/routing/response.py b/emmett/routing/response.py
index a1c23cd8..0d16a20c 100644
--- a/emmett/routing/response.py
+++ b/emmett/routing/response.py
@@ -13,7 +13,7 @@
 
 from typing import Any, Dict, Tuple, Union
 
-from emmett_core.http.response import HTTPResponse, HTTPStringResponse
+from emmett_core.http.response import HTTPStringResponse
 from emmett_core.routing.response import ResponseProcessor
 from renoir.errors import TemplateMissingError
 
diff --git a/pyproject.toml b/pyproject.toml
index f63d9aff..e337cd2c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "emmett"
-version = "2.6.1"
+version = "2.6.2"
 description = "The web framework for inventors"
 readme = "README.md"
 license = "BSD-3-Clause"
@@ -35,7 +35,7 @@ classifiers = [
 
 dependencies = [
     "click>=6.0",
-    "emmett-core[granian,rapidjson]~=1.0.2",
+    "emmett-core[granian,rapidjson]~=1.0.4",
     "emmett-pydal==17.3.1",
     "pendulum~=3.0.0",
     "pyyaml~=6.0",