diff --git a/src/commands/revocation.rs b/src/commands/revocation.rs
index 95e136855db951825364d48b3fb9cf0f12160f0f..20521887004d6d6d847ac5ed039e5866124aa0ef 100644
--- a/src/commands/revocation.rs
+++ b/src/commands/revocation.rs
@@ -6,7 +6,7 @@ use sp_core::sr25519::Signature;
 // use crate::runtime::runtime_types::pallet_identity::types::RevocationPayload;
 type EncodedRevocationPayload = Vec<u8>;
 
-pub fn print_revoc_sig(data: &Data) -> () {
+pub fn print_revoc_sig(data: &Data) {
 	let (_, signature) = generate_revoc_doc(data);
 	println!("revocation payload signature");
 	println!("0x{}", hex::encode(signature));
diff --git a/src/commands/runtime.rs b/src/commands/runtime.rs
index 8238d8c555a804b93cdf9423b7bbc0fe234be64b..2f51e6f6591523a312283fd20d4d9b77343da667 100644
--- a/src/commands/runtime.rs
+++ b/src/commands/runtime.rs
@@ -1,6 +1,6 @@
 use crate::*;
 
-pub async fn runtime_info(data: Data) -> () {
+pub async fn runtime_info(data: Data) {
 	let api = data.client();
 
 	// certifications
diff --git a/src/data.rs b/src/data.rs
index 8639b9d62d6266b95db0bce1b280cc2d6cc5857e..80ee1e0d5f9ea2ebb88efd99122b3b8f567cda78 100644
--- a/src/data.rs
+++ b/src/data.rs
@@ -103,10 +103,12 @@ impl Data {
 	/// build a client from url
 	// TODO get client from a pre-defined list
 	pub async fn build_client(mut self) -> Self {
-		self.client = Some(Client::from_url(&self.args.url).await.expect(&format!(
-			"could not establish connection with the server {}",
-			self.args.url
-		)));
+		self.client = Some(Client::from_url(&self.args.url).await.unwrap_or_else(|_| {
+			panic!(
+				"could not establish connection with the server {}",
+				self.args.url
+			)
+		}));
 		self
 	}
 	/// build an indexer if not disabled