diff --git a/pelican/tools/templates/Makefile.in b/pelican/tools/templates/Makefile.in
index fe7a60a4..aba1173e 100644
--- a/pelican/tools/templates/Makefile.in
+++ b/pelican/tools/templates/Makefile.in
@@ -97,7 +97,9 @@ ftp_upload: publish
 	lftp ftp://$$(FTP_USER)@$$(FTP_HOST) -e "mirror -R $$(OUTPUTDIR) $$(FTP_TARGET_DIR) ; quit"
 
 s3_upload: publish
-	s3cmd sync $(OUTPUTDIR)/ s3://$(S3_BUCKET) --acl-public --delete-removed
+        s3cmd sync $(OUTPUTDIR)/ s3://$(S3_BUCKET) --acl-public --delete-removed --exclude=*.css
+        # Mime-type detection is not always reliable - https://github.com/s3tools/s3cmd/issues/198
+        s3cmd -m text/css sync $(OUTPUTDIR)/ s3://$(S3_BUCKET) --acl-public --delete-removed --include=*.css 
 
 cf_upload: publish
 	cd $(OUTPUTDIR) && swift -v -A https://auth.api.rackspacecloud.com/v1.0 -U $(CLOUDFILES_USERNAME) -K $(CLOUDFILES_API_KEY) upload -c $(CLOUDFILES_CONTAINER) .