diff --git a/odoo/addons/base/ir/ir_http.py b/odoo/addons/base/ir/ir_http.py
index 1d942e75a86..df15e45df22 100644
--- a/odoo/addons/base/ir/ir_http.py
+++ b/odoo/addons/base/ir/ir_http.py
@@ -324,7 +324,7 @@ class IrHttp(models.AbstractModel):
 
         # cache
         etag = hasattr(request, 'httprequest') and request.httprequest.headers.get('If-None-Match')
-        retag = '"%s"' % hashlib.md5(last_update).hexdigest()
+        retag = '"%s"' % hashlib.md5(content).hexdigest()
         status = status or (304 if etag == retag else 200)
         headers.append(('ETag', retag))
         headers.append(('Cache-Control', 'max-age=%s' % (STATIC_CACHE if unique else 0)))