diff --git a/src/helpers/toBasicAuth/toBasicAuth.ts b/src/helpers/toBasicAuth/toBasicAuth.ts
index 77849062..4c40e492 100644
--- a/src/helpers/toBasicAuth/toBasicAuth.ts
+++ b/src/helpers/toBasicAuth/toBasicAuth.ts
@@ -1,6 +1,6 @@
 export function toBasicAuth(username: string, password: string): string {
   const credentials = `${username}:${password}`;
-  if (typeof window !== "undefined" && window.btoa) {
+  if (typeof btoa === "function") {
     return `Basic ${btoa(credentials)}`;
   } else if (typeof Buffer !== "undefined") {
     return `Basic ${Buffer.from(credentials, "binary").toString("base64")}`;
diff --git a/src/helpers/toBasicAuth/toBasicAuth.unit.test.ts b/src/helpers/toBasicAuth/toBasicAuth.unit.test.ts
index 81e2e3d2..a9b51595 100644
--- a/src/helpers/toBasicAuth/toBasicAuth.unit.test.ts
+++ b/src/helpers/toBasicAuth/toBasicAuth.unit.test.ts
@@ -23,8 +23,7 @@ test("converts username and password into Basic Auth header", () => {
 });
 
 test("throws error if environment not supported", () => {
-  if (typeof window !== "undefined") window.btoa = undefined;
-  // eslint-disable-next-line no-global-assign
+  if (typeof btoa === "function") btoa = undefined;
   if (Buffer) Buffer = undefined;
   expect(() => toBasicAuth("", "")).toThrowError();
 });