diff --git a/README.md b/README.md
index f0f98a9..c504f93 100644
--- a/README.md
+++ b/README.md
@@ -71,6 +71,20 @@ $ go install github.com/google/alertmanager-irc-relay
 $ alertmanager-irc-relay --config /path/to/your/config/file
 ```
 
+The configuration file can reference environment variables. It is then possible
+to specify certain parameters directly when running the bot:
+```
+$ cat /path/to/your/config/file
+...
+http_port: $MY_SERVICE_PORT
+...
+irc_nickname_password: $NICKSERV_PASSWORD
+...
+$ export MY_SERVICE_PORT=8000 NICKSERV_PASSWORD=mynickserv_key
+$ alertmanager-irc-relay --config /path/to/your/config/file
+```
+
+
 ### Prometheus configuration
 
 Prometheus can be configured following the official
diff --git a/config.go b/config.go
index 722c896..e554a82 100644
--- a/config.go
+++ b/config.go
@@ -17,6 +17,7 @@ package main
 import (
 	"gopkg.in/yaml.v2"
 	"io/ioutil"
+	"os"
 )
 
 const (
@@ -68,6 +69,7 @@ func LoadConfig(configFile string) (*Config, error) {
 		if err != nil {
 			return nil, err
 		}
+		data = []byte(os.ExpandEnv(string(data)))
 		if err := yaml.Unmarshal(data, config); err != nil {
 			return nil, err
 		}
diff --git a/config_test.go b/config_test.go
index db98312..a029c37 100644
--- a/config_test.go
+++ b/config_test.go
@@ -80,6 +80,35 @@ func TestLoadGoodConfig(t *testing.T) {
 	}
 }
 
+func TestLoadWithEnvironmentVariables(t *testing.T) {
+	expectedNickPass := "mynickpass"
+
+	os.Setenv("NICKSERV_PASSWORD", expectedNickPass)
+	defer os.Clearenv()
+
+	tmpfile, err := ioutil.TempFile("", "airtestenvvarconfig")
+	if err != nil {
+		t.Errorf("Could not create tmpfile for testing: %s", err)
+	}
+	defer os.Remove(tmpfile.Name())
+
+	msgOnceConfigData := []byte("irc_nickname_password: $NICKSERV_PASSWORD")
+	if _, err := tmpfile.Write(msgOnceConfigData); err != nil {
+		t.Errorf("Could not write test data in tmpfile: %s", err)
+	}
+	tmpfile.Close()
+
+	config, err := LoadConfig(tmpfile.Name())
+	if config == nil {
+		t.Errorf("Expected a config, got: %s", err)
+	}
+
+	if config.IRCNickPass != expectedNickPass {
+		t.Errorf("Loaded unexpected value: %s (expected: %s)",
+			config.IRCNickPass, expectedNickPass)
+	}
+}
+
 func TestLoadBadFile(t *testing.T) {
 	tmpfile, err := ioutil.TempFile("", "airtestbadfile")
 	if err != nil {