diff --git a/CODE_OF_CONDUCT.md b/CODE_OF_CONDUCT.md
index 4a80595..68080cf 100644
--- a/CODE_OF_CONDUCT.md
+++ b/CODE_OF_CONDUCT.md
@@ -40,7 +40,7 @@ Project maintainers who do not follow or enforce the Code of Conduct in good fai
 
 ## Attribution
 
-This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4, available at [http://contributor-covenant.org/version/1/4][version]
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4, available at [https://www.contributor-covenant.org/version/1/4][version]
 
-[homepage]: http://contributor-covenant.org
-[version]: http://contributor-covenant.org/version/1/4/
+[homepage]: https://www.contributor-covenant.org
+[version]: https://www.contributor-covenant.org/version/1/4/
diff --git a/Cargo.toml b/Cargo.toml
index d859d7e..94684c3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,7 +3,7 @@ name = "lettre"
 version = "0.9.2" # remember to update html_root_url
 description = "Email client"
 readme = "README.md"
-homepage = "http://lettre.at"
+homepage = "https://lettre.at"
 repository = "https://github.com/lettre/lettre"
 license = "MIT"
 authors = ["Alexis Mousset <contact@amousset.me>"]
diff --git a/README.md b/README.md
index 8f17ea0..4159775 100644
--- a/README.md
+++ b/README.md
@@ -11,12 +11,12 @@
 [![MIT licensed](https://img.shields.io/badge/license-MIT-blue.svg)](./LICENSE)
 
 [![Gitter](https://badges.gitter.im/lettre/lettre.svg)](https://gitter.im/lettre/lettre?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
-[![Average time to resolve an issue](http://isitmaintained.com/badge/resolution/lettre/lettre.svg)](http://isitmaintained.com/project/lettre/lettre "Average time to resolve an issue")
-[![Percentage of issues still open](http://isitmaintained.com/badge/open/lettre/lettre.svg)](http://isitmaintained.com/project/lettre/lettre "Percentage of issues still open")
+[![Average time to resolve an issue](https://isitmaintained.com/badge/resolution/lettre/lettre.svg)](https://isitmaintained.com/project/lettre/lettre "Average time to resolve an issue")
+[![Percentage of issues still open](https://isitmaintained.com/badge/open/lettre/lettre.svg)](https://isitmaintained.com/project/lettre/lettre "Percentage of issues still open")
 
 Useful links:
 
-* [User documentation](http://lettre.at/)
+* [User documentation](https://lettre.at/)
 * [API documentation](https://docs.rs/lettre/)
 * [Changelog](https://github.com/lettre/lettre/blob/master/CHANGELOG.md)