diff --git a/cmd/setup.go b/cmd/setup.go
index 12e14a9..cde4bc9 100644
--- a/cmd/setup.go
+++ b/cmd/setup.go
@@ -43,9 +43,9 @@ func createAcmeClient(ctx *cli.Context, enableHTTPServer bool, challengeCache ca
 	if (!acmeAcceptTerms || dnsProvider == "") && acmeAPI != "https://acme.mock.directory" {
 		return nil, fmt.Errorf("%w: you must set $ACME_ACCEPT_TERMS and $DNS_PROVIDER, unless $ACME_API is set to https://acme.mock.directory", ErrAcmeMissConfig)
 	}
-	if len(acmeEabHmac) != 0 && len(acmeEabKID) == 0 {
+	if acmeEabHmac != "" && acmeEabKID == "" {
 		return nil, fmt.Errorf("%w: ACME_EAB_HMAC also needs ACME_EAB_KID to be set", ErrAcmeMissConfig)
-	} else if len(acmeEabHmac) == 0 && len(acmeEabKID) != 0 {
+	} else if acmeEabHmac == "" && acmeEabKID != "" {
 		return nil, fmt.Errorf("%w: ACME_EAB_KID also needs ACME_EAB_HMAC to be set", ErrAcmeMissConfig)
 	}