diff --git a/README.md b/README.md
index 9394567..5269e19 100644
--- a/README.md
+++ b/README.md
@@ -25,6 +25,15 @@ TLSPROXY_KEY_FILE=server.key \
 tlsproxy
 ```
 
+## Environment variable
+
+Environment             | Description
+----------------------- | -----------
+`TLSPROXY_TARGET`       | Address of the host.
+`TLSPROXY_PORTS`        | The ports you want to listen to with TLS. Multiple ports are allowed using a comma as separator with the following syntax: `<outside>:<inside>` _(example `443:80`)_ or `<same-auto-side-inside>` _(example `8000`)_.
+`TLSPROXY_CERT_FILE`    | Path to the certificate file _(example `/certs/server.crt`)_.
+`TLSPROXY_KEY_FILE`     | Path to the key file _(example `/certs/server.key`)_.
+
 ## Certificates
 
 For testing, one can create certificates using the following commands:
diff --git a/certificates/server.crt b/certificates/server.crt
deleted file mode 100644
index 07b5656..0000000
--- a/certificates/server.crt
+++ /dev/null
@@ -1,13 +0,0 @@
------BEGIN CERTIFICATE-----
-MIIB5zCCAW6gAwIBAgIUUvqk47JSIGSA84UGdzFRotsS/h8wCgYIKoZIzj0EAwIw
-KzELMAkGA1UEBhMCTkwxDTALBgNVBAgMBERlbW8xDTALBgNVBAoMBERlbW8wHhcN
-MjMxMTMwMDgxNzEyWhcNMzMxMTI3MDgxNzEyWjArMQswCQYDVQQGEwJOTDENMAsG
-A1UECAwERGVtbzENMAsGA1UECgwERGVtbzB2MBAGByqGSM49AgEGBSuBBAAiA2IA
-BBWwKHYC8902TfiBJ4w8drbaQLJyuJ8STEWvO2Dt2uQE2PtWOyaISvOL4pR4nPkh
-HXAEP2N8f/IHrx1vLM3wf3UU9ZYQibmQaCYnA7oXv+rxXmlZH6t7XbHviH8Un7EV
-kqNTMFEwHQYDVR0OBBYEFBF6RBvYpFjGHRQ9G7VC0ITIQqCpMB8GA1UdIwQYMBaA
-FBF6RBvYpFjGHRQ9G7VC0ITIQqCpMA8GA1UdEwEB/wQFMAMBAf8wCgYIKoZIzj0E
-AwIDZwAwZAIwKL7Z+KMk78B1U2CtR2OoUKiv0KsNyRyH8eiaoxfh7TDlhAJrCpA9
-wJOISmX53E9iAjAhG6F/3OzkH/mVfJTDsXkOdzlMhCPKuJimLJKGChJuoxKAB0nP
-SFc2683PGmZ5miQ=
------END CERTIFICATE-----
diff --git a/certificates/server.key b/certificates/server.key
deleted file mode 100644
index ca64437..0000000
--- a/certificates/server.key
+++ /dev/null
@@ -1,9 +0,0 @@
------BEGIN EC PARAMETERS-----
-BgUrgQQAIg==
------END EC PARAMETERS-----
------BEGIN EC PRIVATE KEY-----
-MIGkAgEBBDCAdFLxBE1sq15KbA42cJejnKfY3nvqmDvac6N63ZtLdwVRZVe6HwEU
-+IFRHEWHCO6gBwYFK4EEACKhZANiAAQVsCh2AvPdNk34gSeMPHa22kCycrifEkxF
-rztg7drkBNj7VjsmiErzi+KUeJz5IR1wBD9jfH/yB68dbyzN8H91FPWWEIm5kGgm
-JwO6F7/q8V5pWR+re12x74h/FJ+xFZI=
------END EC PRIVATE KEY-----