diff --git a/watermelon/src/client/builder.rs b/watermelon/src/client/builder.rs
index 1cae804..81143dd 100644
--- a/watermelon/src/client/builder.rs
+++ b/watermelon/src/client/builder.rs
@@ -94,7 +94,7 @@ impl ClientBuilder {
                     password,
                 }));
             }
-            from_env::AuthenticationMethod::None => {
+            from_env::AuthenticationMethod::None {} => {
                 this = this.authentication_method(None);
             }
         }
diff --git a/watermelon/src/client/from_env.rs b/watermelon/src/client/from_env.rs
index d67071f..b9a7eb0 100644
--- a/watermelon/src/client/from_env.rs
+++ b/watermelon/src/client/from_env.rs
@@ -30,7 +30,7 @@ pub(super) enum AuthenticationMethod {
         #[serde(rename = "nats_password")]
         password: String,
     },
-    None,
+    None {},
 }
 
 fn deserialize_nkey<'de, D>(deserializer: D) -> Result<KeyPair, D::Error>
@@ -40,3 +40,69 @@ where
     let secret = String::deserialize(deserializer)?;
     KeyPair::from_encoded_seed(&secret).map_err(de::Error::custom)
 }
+
+#[cfg(test)]
+mod tests {
+    use claims::{assert_matches, assert_ok};
+
+    use super::{AuthenticationMethod, FromEnv};
+
+    const TEST_SEED: &str = "SAAPN4W3EG6KCJGUQTKTJ5GSB5NHK5CHAJL4DBGFUM3HHROI4XUEP4OBK4";
+    const TEST_PUBLIC_KEY: &str = "SAAJYMSGSUUUC3GAOKL2IFAAKQDV32K4X45HPCPC4EBM7F7N76HQGR4C2I";
+
+    fn from_iter<const N: usize>(vars: [(&str, &str); N]) -> FromEnv {
+        let iter = vars.into_iter().map(|(k, v)| (k.to_owned(), v.to_owned()));
+        assert_ok!(envy::from_iter::<_, FromEnv>(iter))
+    }
+
+    #[test]
+    fn deserialize_creds() {
+        let env = from_iter([
+            ("NATS_JWT", "eyJhbGciOiJlZDI1NTE5In0"),
+            ("NATS_NKEY", TEST_SEED),
+        ]);
+        assert_matches!(
+            env.auth,
+            AuthenticationMethod::Creds { jwt, nkey }
+                if jwt == "eyJhbGciOiJlZDI1NTE5In0"
+                    && nkey.public_key().to_string() == TEST_PUBLIC_KEY
+        );
+        assert!(env.inbox_prefix.is_none());
+    }
+
+    #[test]
+    fn deserialize_creds_file() {
+        let env = from_iter([("NATS_CREDS_FILE", "/etc/nats/user.creds")]);
+        assert_matches!(
+            env.auth,
+            AuthenticationMethod::CredsFile { creds_file }
+                if creds_file.as_os_str() == "/etc/nats/user.creds"
+        );
+        assert!(env.inbox_prefix.is_none());
+    }
+
+    #[test]
+    fn deserialize_user_and_password() {
+        let env = from_iter([("NATS_USERNAME", "alice"), ("NATS_PASSWORD", "hunter2")]);
+        assert_matches!(
+            env.auth,
+            AuthenticationMethod::UserAndPassword { username, password }
+                if username == "alice" && password == "hunter2"
+        );
+        assert!(env.inbox_prefix.is_none());
+    }
+
+    #[test]
+    fn deserialize_none() {
+        let env = from_iter([]);
+        assert_matches!(env.auth, AuthenticationMethod::None {});
+        assert!(env.inbox_prefix.is_none());
+    }
+
+    #[test]
+    fn deserialize_none_with_inbox_prefix() {
+        let env = from_iter([("INBOX_PREFIX", "_CUSTOM_INBOX")]);
+        assert_matches!(env.auth, AuthenticationMethod::None {});
+        assert_eq!(env.inbox_prefix.unwrap().as_str(), "_CUSTOM_INBOX");
+    }
+}