diff --git a/src/main/java/com/google/genai/ApiClient.java b/src/main/java/com/google/genai/ApiClient.java
index 68666eceaa8..e6ccb9fbf75 100644
--- a/src/main/java/com/google/genai/ApiClient.java
+++ b/src/main/java/com/google/genai/ApiClient.java
@@ -104,7 +104,7 @@ abstract class ApiClient {
       throw new IllegalArgumentException("Location must not be empty.");
     }
 
-    this.credentials = Optional.of(credentials.orElse(defaultCredentials()));
+    this.credentials = Optional.of(credentials.orElseGet(() -> defaultCredentials()));
 
     this.httpOptions = defaultHttpOptions(/* vertexAI= */ true, this.location);