diff --git a/README.md b/README.md
index 205a11b..636a725 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@ Calculate cost of electricity.
 
 ## How to use
 
-```shell
+```console
 $ kwh-cost [OPTIONS] price wattage interval [interval ..]
 ```
 
@@ -17,7 +17,7 @@ Options are `-v, --version` to show program's version; and `-h, --help` to show
 
 Here is an example:
 
-```shell
+```console
 $ kwh-cost 3.68 120 30d 2h
 ```