diff --git a/doc/styleguide.md b/doc/styleguide.md
index 468a11290bad3a029d33fa161892d78075b9fa69..8eba08539f522e76337a55b8c688caab6dfbfeeb 100644
--- a/doc/styleguide.md
+++ b/doc/styleguide.md
@@ -164,6 +164,7 @@ This style guide is taken, modified and enhanced from [DUNE](https://dune-projec
     else
         return 1.0; // ok, one-liner
     ```
+* __Numbers__: Write `1.0` not `1.` for better readability
 
 ### Namespaces