diff --git a/README.md b/README.md
index 555a4773c..e9d962815 100644
--- a/README.md
+++ b/README.md
@@ -171,7 +171,7 @@ See **config_example.yaml** :
 #listenaddress: "" # ip address to bind falcosidekick to (default: "" meaning all addresses)
 #listenport: 2801 # port to listen for daemon (default: 2801)
 debug: false # if true all outputs will print in stdout the payload they send (default: false)
-customfields: # custom fields are added to falco events
+customfields: # custom fields are added to falco events, if the value starts with % the relative env var is used
   Akey: "AValue"
   Bkey: "BValue"
   Ckey: "CValue"
@@ -520,7 +520,7 @@ care of lower/uppercases**) : `yaml: a.b --> envvar: A_B` :
 - **LISTENPORT** : port to listen for daemon (default: `2801`)
 - **DEBUG** : if _true_ all outputs will print in stdout the payload they send
   (default: false)
-- **CUSTOMFIELDS** : a list of comma separated custom fields to add to falco
+- **CUSTOMFIELDS** : a list of comma separated custom fields to add to falco, if the value starts with % the relative env var is used
   events, syntax is "key:value,key:value"
   **MUTUALTLSFILESPATH**: path which will be used to stored certs and key for mutual tls authentication (default: "/etc/certs")
 - **SLACK_WEBHOOKURL** : Slack Webhook URL (ex:
diff --git a/config.go b/config.go
index bc7f384e4..35e41fee5 100644
--- a/config.go
+++ b/config.go
@@ -374,7 +374,15 @@ func getConfig() *types.Configuration {
 		for _, label := range customfields {
 			tagkeys := strings.Split(label, ":")
 			if len(tagkeys) == 2 {
-				c.Customfields[tagkeys[0]] = tagkeys[1]
+				if strings.HasPrefix(tagkeys[1], "%") {
+					if s := os.Getenv(tagkeys[1][1:]); s != "" {
+						c.Customfields[tagkeys[0]] = s
+					} else {
+						log.Printf("[ERROR] : Can't find env var %v for custom fields", tagkeys[1][1:])
+					}
+				} else {
+					c.Customfields[tagkeys[0]] = tagkeys[1]
+				}
 			}
 		}
 	}
diff --git a/config_example.yaml b/config_example.yaml
index b0707efe9..3d30e72a7 100644
--- a/config_example.yaml
+++ b/config_example.yaml
@@ -1,7 +1,7 @@
 #listenaddress: "" # ip address to bind falcosidekick to (default: "" meaning all addresses)
 #listenport: 2801 # port to listen for daemon (default: 2801)
 debug: false # if true all outputs will print in stdout the payload they send (default: false)
-customfields: # custom fields are added to falco events and metrics
+customfields: # custom fields are added to falco events and metrics, if the value starts with % the relative env var is used
   Akey: "AValue"
   Bkey: "BValue"
   Ckey: "CValue"