diff --git a/README.md b/README.md
index 8b6edbd..47dcdb9 100644
--- a/README.md
+++ b/README.md
@@ -54,7 +54,7 @@ use mistralai_client::v1::client::Client;
 fn main() {
     let api_key = "your_api_key";
 
-    let client = Client::new(Some(api_key), None, None, None);
+    let client = Client::new(Some(api_key), None, None, None).unwrap();
 }
 ```
 
@@ -71,7 +71,7 @@ use mistralai_client::v1::{
 
 fn main() {
     // This example suppose you have set the `MISTRAL_API_KEY` environment variable.
-    let client = Client::new(None, None, None, None);
+    let client = Client::new(None, None, None, None).unwrap();
 
     let model = Model::OpenMistral7b;
     let messages = vec![ChatCompletionMessage {
@@ -101,7 +101,7 @@ use mistralai_client::v1::{client::Client, constants::EmbedModel};
 
 fn main() {
     // This example suppose you have set the `MISTRAL_API_KEY` environment variable.
-  let client: Client = Client::new(None, None, None, None);
+  let client: Client = Client::new(None, None, None, None).unwrap();
 
   let model = EmbedModel::MistralEmbed;
   let input = vec!["Embed this sentence.", "As well as this one."]
@@ -123,7 +123,7 @@ use mistralai_client::v1::client::Client;
 
 fn main() {
     // This example suppose you have set the `MISTRAL_API_KEY` environment variable.
-    let client = Client::new(None, None, None, None);
+    let client = Client::new(None, None, None, None).unwrap();
 
     let result = client.list_models().unwrap();
     println!("First Model ID: {:?}", result.data[0].id);
diff --git a/src/v1/client.rs b/src/v1/client.rs
index 9248c2c..7f32f2f 100644
--- a/src/v1/client.rs
+++ b/src/v1/client.rs
@@ -24,21 +24,21 @@ impl Client {
         endpoint: Option<String>,
         max_retries: Option<u32>,
         timeout: Option<u32>,
-    ) -> Self {
-        let api_key = api_key.unwrap_or(
-            std::env::var("MISTRAL_API_KEY")
-                .unwrap_or_else(|_| panic!("{}", ClientError::ApiKeyError)),
-        );
+    ) -> Result<Self, ClientError> {
+        let api_key = api_key.unwrap_or(match std::env::var("MISTRAL_API_KEY") {
+            Ok(api_key_from_env) => api_key_from_env,
+            Err(_) => return Err(ClientError::ApiKeyError),
+        });
         let endpoint = endpoint.unwrap_or(API_URL_BASE.to_string());
         let max_retries = max_retries.unwrap_or(5);
         let timeout = timeout.unwrap_or(120);
 
-        Self {
+        Ok(Self {
             api_key,
             endpoint,
             max_retries,
             timeout,
-        }
+        })
     }
 
     pub fn build_request(&self, request: minreq::Request) -> minreq::Request {
diff --git a/src/v1/error.rs b/src/v1/error.rs
index 74f3893..c5f12cf 100644
--- a/src/v1/error.rs
+++ b/src/v1/error.rs
@@ -12,7 +12,7 @@ impl fmt::Display for ApiError {
 }
 impl Error for ApiError {}
 
-#[derive(Debug, thiserror::Error)]
+#[derive(Debug, PartialEq, thiserror::Error)]
 pub enum ClientError {
     #[error("You must either set the `MISTRAL_API_KEY` environment variable or specify it in `Client::new(api_key, ...).")]
     ApiKeyError,
diff --git a/tests/v1_client_chat_test.rs b/tests/v1_client_chat_test.rs
index d7cc9b6..6ae3909 100644
--- a/tests/v1_client_chat_test.rs
+++ b/tests/v1_client_chat_test.rs
@@ -7,7 +7,7 @@ use mistralai_client::v1::{
 
 #[test]
 fn test_client_chat() {
-    let client = Client::new(None, None, None, None);
+    let client = Client::new(None, None, None, None).unwrap();
 
     let model = Model::OpenMistral7b;
     let messages = vec![ChatCompletionMessage {
diff --git a/tests/v1_client_embeddings_test.rs b/tests/v1_client_embeddings_test.rs
index 2c21ba6..bb32fa4 100644
--- a/tests/v1_client_embeddings_test.rs
+++ b/tests/v1_client_embeddings_test.rs
@@ -3,7 +3,7 @@ use mistralai_client::v1::{client::Client, constants::EmbedModel};
 
 #[test]
 fn test_client_embeddings() {
-    let client: Client = Client::new(None, None, None, None);
+    let client: Client = Client::new(None, None, None, None).unwrap();
 
     let model = EmbedModel::MistralEmbed;
     let input = vec!["Embed this sentence.", "As well as this one."]
diff --git a/tests/v1_client_list_models_test.rs b/tests/v1_client_list_models_test.rs
index 299866a..6a6e8ef 100644
--- a/tests/v1_client_list_models_test.rs
+++ b/tests/v1_client_list_models_test.rs
@@ -3,7 +3,7 @@ use mistralai_client::v1::client::Client;
 
 #[test]
 fn test_client_list_models() {
-    let client = Client::new(None, None, None, None);
+    let client = Client::new(None, None, None, None).unwrap();
 
     let response = client.list_models().unwrap();
 
diff --git a/tests/v1_client_new_test.rs b/tests/v1_client_new_test.rs
index e461447..ca69e41 100644
--- a/tests/v1_client_new_test.rs
+++ b/tests/v1_client_new_test.rs
@@ -1,5 +1,5 @@
 use jrest::expect;
-use mistralai_client::v1::client::Client;
+use mistralai_client::v1::{client::Client, error::ClientError};
 
 #[test]
 fn test_client_new_with_none_params() {
@@ -7,7 +7,7 @@ fn test_client_new_with_none_params() {
     std::env::remove_var("MISTRAL_API_KEY");
     std::env::set_var("MISTRAL_API_KEY", "test_api_key_from_env");
 
-    let client = Client::new(None, None, None, None);
+    let client = Client::new(None, None, None, None).unwrap();
 
     expect!(client.api_key).to_be("test_api_key_from_env".to_string());
     expect!(client.endpoint).to_be("https://api.mistral.ai/v1".to_string());
@@ -38,7 +38,8 @@ fn test_client_new_with_all_params() {
         endpoint.clone(),
         max_retries.clone(),
         timeout.clone(),
-    );
+    )
+    .unwrap();
 
     expect!(client.api_key).to_be(api_key.unwrap());
     expect!(client.endpoint).to_be(endpoint.unwrap());
@@ -54,12 +55,16 @@ fn test_client_new_with_all_params() {
 }
 
 #[test]
-#[should_panic]
 fn test_client_new_with_missing_api_key() {
     let maybe_original_mistral_api_key = std::env::var("MISTRAL_API_KEY").ok();
     std::env::remove_var("MISTRAL_API_KEY");
 
-    let _client = Client::new(None, None, None, None);
+    let call = || Client::new(None, None, None, None);
+
+    match call() {
+        Ok(_) => panic!("Expected `ClientError::ApiKeyError` but got Ok.`"),
+        Err(error) => assert_eq!(error, ClientError::ApiKeyError),
+    }
 
     match maybe_original_mistral_api_key {
         Some(original_mistral_api_key) => {