diff --git a/.idea/misc.xml b/.idea/misc.xml
index ed4c707..96c631b 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -3,5 +3,5 @@
   <component name="JavaScriptSettings">
     <option name="languageLevel" value="ES6" />
   </component>
-  <component name="ProjectRootManager" version="2" project-jdk-name="Python 3.8 (sharpei)" project-jdk-type="Python SDK" />
+  <component name="ProjectRootManager" version="2" project-jdk-name="Python 3.6 (sharpei)" project-jdk-type="Python SDK" />
 </project>
\ No newline at end of file
diff --git a/.idea/sharpei.iml b/.idea/sharpei.iml
index 66cbf2d..1d5a2ae 100644
--- a/.idea/sharpei.iml
+++ b/.idea/sharpei.iml
@@ -3,8 +3,9 @@
   <component name="NewModuleRootManager">
     <content url="file://$MODULE_DIR$">
       <excludeFolder url="file://$MODULE_DIR$/.venv" />
+      <excludeFolder url="file://$MODULE_DIR$/venv" />
     </content>
-    <orderEntry type="jdk" jdkName="Python 3.8 (sharpei)" jdkType="Python SDK" />
+    <orderEntry type="jdk" jdkName="Python 3.6 (sharpei)" jdkType="Python SDK" />
     <orderEntry type="sourceFolder" forTests="false" />
   </component>
   <component name="TestRunnerService">
diff --git a/sharpei/handler.py b/sharpei/handler.py
index 0d7d783..2300833 100644
--- a/sharpei/handler.py
+++ b/sharpei/handler.py
@@ -2,6 +2,7 @@
 from os import path
 from typing import Union
 import logging
+import mimetypes
 
 from watchdog import events
 import boto3
@@ -42,11 +43,16 @@ def _relative_s3_filename(self, filename: str) -> str:
     def s3_upload(self, file_path: str):
         upload_key = self.base_key + self._relative_s3_filename(file_path)
         logger.info(f"Upload {file_path} to s3://{self.bucket}/{upload_key}")
+        extra_args = self.s3_args.copy()
+        mimetype, _ = mimetypes.guess_type(file_path)
+        if mimetype:
+            extra_args["ContentType"] = mimetype
+
         s3_client.upload_file(
             Filename=file_path,
             Bucket=self.bucket,
             Key=upload_key,
-            ExtraArgs=self.s3_args,
+            ExtraArgs=extra_args,
         )
 
     def on_any_event(self, event: events.FileSystemEvent):