diff --git a/addons/web/static/src/css/base.css b/addons/web/static/src/css/base.css
index 75ca1270238..90c7603c097 100644
--- a/addons/web/static/src/css/base.css
+++ b/addons/web/static/src/css/base.css
@@ -1,3 +1,4 @@
+@charset "utf-8";
 @font-face {
   font-family: "mnmliconsRegular";
   src: url("/web/static/src/font/mnmliconsv21-webfont.eot") format("eot");
diff --git a/addons/web/static/src/css/base.sass b/addons/web/static/src/css/base.sass
index 93deeec6398..b4be8931f87 100644
--- a/addons/web/static/src/css/base.sass
+++ b/addons/web/static/src/css/base.sass
@@ -1,3 +1,4 @@
+@charset "utf-8"
 
 // Variables {{{
 $facets-border: #afafb6