diff --git a/storages/backends/s3boto3.py b/storages/backends/s3boto3.py
index 1ada4936e..327f56743 100644
--- a/storages/backends/s3boto3.py
+++ b/storages/backends/s3boto3.py
@@ -434,8 +434,9 @@ def _save(self, name, content):
         cleaned_name = self._clean_name(name)
         name = self._normalize_name(cleaned_name)
         parameters = self.object_parameters.copy()
+        _type, encoding = mimetypes.guess_type(name)
         content_type = getattr(content, 'content_type',
-                               mimetypes.guess_type(name)[0] or self.default_content_type)
+                               _type or self.default_content_type)
 
         # setting the content_type in the key object is not enough.
         parameters.update({'ContentType': content_type})
@@ -443,6 +444,9 @@ def _save(self, name, content):
         if self.gzip and content_type in self.gzip_content_types:
             content = self._compress_content(content)
             parameters.update({'ContentEncoding': 'gzip'})
+        elif encoding:
+            # If the content already has a particular encoding, set it
+            parameters.update({'ContentEncoding': encoding})
 
         encoded_name = self._encode_name(name)
         obj = self.bucket.Object(encoded_name)
diff --git a/tests/test_s3boto3.py b/tests/test_s3boto3.py
index 09e823b4a..7bfdc95a2 100644
--- a/tests/test_s3boto3.py
+++ b/tests/test_s3boto3.py
@@ -126,6 +126,23 @@ def test_storage_save(self):
             }
         )
 
+    def test_storage_save_gzipped(self):
+        """
+        Test saving a gzipped file
+        """
+        name = 'test_storage_save.gz'
+        content = ContentFile("I am gzip'd")
+        self.storage.save(name, content)
+        obj = self.storage.bucket.Object.return_value
+        obj.upload_fileobj.assert_called_with(
+            content,
+            ExtraArgs={
+                'ContentType': 'application/octet-stream',
+                'ContentEncoding': 'gzip',
+                'ACL': self.storage.default_acl,
+            }
+        )
+
     def test_storage_save_gzip(self):
         """
         Test saving a file with gzip enabled.