diff --git a/gns3server/web/response.py b/gns3server/web/response.py
index 7b3e287a..d786b874 100644
--- a/gns3server/web/response.py
+++ b/gns3server/web/response.py
@@ -120,7 +120,7 @@ class Response(aiohttp.web.Response):
 
         st = os.stat(path)
         self.last_modified = st.st_mtime
-        self.enable_chunked_encoding()
+        self.headers[aiohttp.hdrs.CONTENT_LENGTH] = str(st.st_size)
 
         with open(path, 'rb') as fobj:
             yield from self.prepare(self._request)
diff --git a/tests/handlers/api/controller/test_symbol.py b/tests/handlers/api/controller/test_symbol.py
index e44a0489..cd6f15b2 100644
--- a/tests/handlers/api/controller/test_symbol.py
+++ b/tests/handlers/api/controller/test_symbol.py
@@ -36,6 +36,7 @@ def test_get(http_controller):
     response = http_controller.get('/symbols/' + urllib.parse.quote(':/symbols/firewall.svg') + '/raw')
     assert response.status == 200
     assert response.headers['CONTENT-TYPE'] == 'image/svg+xml'
+    assert response.headers['CONTENT-LENGTH'] == '9381'
     assert '</svg>' in response.html
 
     # Reply by the default symbol