diff --git a/src/client.js b/src/client.js
index c8239da..e8e9bd2 100644
--- a/src/client.js
+++ b/src/client.js
@@ -1,9 +1,21 @@
 let isNode = false;
-if (typeof window === 'undefined' || typeof globalThis.fetch !== 'undefined') {
-  globalThis.fetch = (await import('node-fetch')).default;
-  isNode = true;
+
+/**
+ * Initialize fetch
+ * @return {Promise<void>}
+ */
+async function initializeFetch() {
+  if (typeof window === 'undefined' ||
+    typeof globalThis.fetch === 'undefined') {
+    const nodeFetch = await import('node-fetch');
+    fetch = nodeFetch.default;
+    isNode = true;
+  } else {
+    fetch = globalThis.fetch;
+  }
 }
 
+initializeFetch();
 
 const RETRY_STATUS_CODES = [429, 500, 502, 503, 504];
 const ENDPOINT = 'https://api.mistral.ai';