diff --git a/acmed/src/certificate.rs b/acmed/src/certificate.rs
index 1079219..28a2e4e 100644
--- a/acmed/src/certificate.rs
+++ b/acmed/src/certificate.rs
@@ -139,7 +139,6 @@ impl Certificate {
     ) -> Result<(ChallengeHookData, HookType), Error> {
         let challenge = self.get_domain_challenge(domain)?;
         let hook_data = ChallengeHookData {
-            algorithm: self.algo.to_string(),
             challenge: challenge.to_string(),
             domain: domain.to_string(),
             file_name: file_name.to_string(),
diff --git a/acmed/src/hooks.rs b/acmed/src/hooks.rs
index 728af6f..64f097d 100644
--- a/acmed/src/hooks.rs
+++ b/acmed/src/hooks.rs
@@ -19,7 +19,6 @@ pub struct PostOperationHookData {
 #[derive(Serialize)]
 pub struct ChallengeHookData {
     pub domain: String,
-    pub algorithm: String,
     pub challenge: String,
     pub file_name: String,
     pub proof: String,