diff --git a/pillar/api/file_storage_backends/abstract.py b/pillar/api/file_storage_backends/abstract.py
index 3d02dc34..60501a24 100644
--- a/pillar/api/file_storage_backends/abstract.py
+++ b/pillar/api/file_storage_backends/abstract.py
@@ -132,12 +132,19 @@ class Blob(metaclass=abc.ABCMeta):
                                   file_size=file_size)
 
     @abc.abstractmethod
-    def update_filename(self, filename: str):
+    def update_filename(self, filename: str, *, is_attachment=True):
         """Sets the filename which is used when downloading the file.
         
         Not all storage backends support this, and will use the on-disk filename instead.
         """
 
+    @abc.abstractmethod
+    def update_content_type(self, content_type: str, content_encoding: str = ''):
+        """Set the content type (and optionally content encoding).
+
+        Not all storage backends support this.
+        """
+
     @abc.abstractmethod
     def get_url(self, *, is_public: bool) -> str:
         """Returns the URL to access this blob.
diff --git a/pillar/api/file_storage_backends/gcs.py b/pillar/api/file_storage_backends/gcs.py
index 7ecda06e..997d4487 100644
--- a/pillar/api/file_storage_backends/gcs.py
+++ b/pillar/api/file_storage_backends/gcs.py
@@ -174,7 +174,7 @@ class GoogleCloudStorageBlob(Blob):
         self.gblob.reload()
         self._size_in_bytes = self.gblob.size
 
-    def update_filename(self, filename: str):
+    def update_filename(self, filename: str, *, is_attachment=True):
         """Set the ContentDisposition metadata so that when a file is downloaded
         it has a human-readable name.
         """
@@ -182,7 +182,17 @@ class GoogleCloudStorageBlob(Blob):
         if '"' in filename:
             raise ValueError(f'Filename is not allowed to have double quote in it: {filename!r}')
 
-        self.gblob.content_disposition = f'attachment; filename="{filename}"'
+        if is_attachment:
+            self.gblob.content_disposition = f'attachment; filename="{filename}"'
+        else:
+            self.gblob.content_disposition = f'filename="{filename}"'
+        self.gblob.patch()
+
+    def update_content_type(self, content_type: str, content_encoding: str = ''):
+        """Set the content type (and optionally content encoding)."""
+
+        self.gblob.content_type = content_type
+        self.gblob.content_encoding = content_encoding
         self.gblob.patch()
 
     def get_url(self, *, is_public: bool) -> str:
diff --git a/pillar/api/file_storage_backends/local.py b/pillar/api/file_storage_backends/local.py
index 70d578a8..9bc1c1ee 100644
--- a/pillar/api/file_storage_backends/local.py
+++ b/pillar/api/file_storage_backends/local.py
@@ -113,10 +113,13 @@ class LocalBlob(Blob):
 
         self._size_in_bytes = file_size
 
-    def update_filename(self, filename: str):
+    def update_filename(self, filename: str, *, is_attachment=True):
         # TODO: implement this for local storage.
         self._log.info('update_filename(%r) not supported', filename)
 
+    def update_content_type(self, content_type: str, content_encoding: str = ''):
+        self._log.info('update_content_type(%r, %r) not supported', content_type, content_encoding)
+
     def make_public(self):
         # No-op on this storage backend.
         pass