diff --git a/acme/client.go b/acme/client.go
index 9ba405b8..1927981a 100644
--- a/acme/client.go
+++ b/acme/client.go
@@ -34,7 +34,7 @@ type User interface {
 
 type solver interface {
 	CanSolve() bool
-	Solve(challenge)
+	Solve(challenge challenge, domain string)
 }
 
 // Client is the user-friendy way to ACME
diff --git a/acme/dvsni_challenge.go b/acme/dvsni_challenge.go
index 1eeda0f1..214d0c1c 100644
--- a/acme/dvsni_challenge.go
+++ b/acme/dvsni_challenge.go
@@ -6,6 +6,6 @@ func (s *dvsniChallenge) CanSolve() bool {
 	return false
 }
 
-func (s *dvsniChallenge) Solve(challenge challenge) {
+func (s *dvsniChallenge) Solve(challenge challenge, domain string) {
 
 }
diff --git a/acme/simple_http_challenge.go b/acme/simple_http_challenge.go
index e7cf3e4f..afaa1c40 100644
--- a/acme/simple_http_challenge.go
+++ b/acme/simple_http_challenge.go
@@ -7,5 +7,6 @@ func (s *simpleHTTPChallenge) CanSolve() bool {
 }
 
 func (s *simpleHTTPChallenge) Solve(challenge challenge) {
+func (s *simpleHTTPChallenge) Solve(chlng challenge, domain string) {
 
 }