diff --git a/doc/html/rst.css b/doc/html/rst.css
index 8a55b61..e8c52ae 100755
--- a/doc/html/rst.css
+++ b/doc/html/rst.css
@@ -13,3 +13,16 @@ img {
   vertical-align: middle
 }
 
+PRE
+{
+    FONT-FAMILY: monospace ;
+}
+
+CODE
+{
+    FONT-FAMILY: monospace;
+}
+.pre
+{
+   FONT-FAMILY: monospace;
+}