diff --git a/lombok.config b/lombok.config
index 8f7e8aa1..b7a0263e 100644
--- a/lombok.config
+++ b/lombok.config
@@ -1 +1,2 @@
-lombok.addLombokGeneratedAnnotation = true
\ No newline at end of file
+lombok.addLombokGeneratedAnnotation = true
+lombok.nonNull.exceptionType = NullPointerException
diff --git a/src/main/java/com/amadeus/Amadeus.java b/src/main/java/com/amadeus/Amadeus.java
index 8dc63f11..ad804b4f 100644
--- a/src/main/java/com/amadeus/Amadeus.java
+++ b/src/main/java/com/amadeus/Amadeus.java
@@ -1,7 +1,6 @@
 package com.amadeus;
 
 import java.util.Map;
-import lombok.NonNull;
 
 /**
  * <p>
@@ -138,7 +137,13 @@ protected Amadeus(Configuration configuration) {
    * @param clientSecret Your API com.amadeus.client credential secret
    * @return a Configuration object
    */
-  public static Configuration builder(@NonNull String clientId, @NonNull String clientSecret) {
+  public static Configuration builder(String clientId, String clientSecret) {
+    if (clientId == null) {
+      throw new IllegalArgumentException("clientId can't be null");
+    }
+    if (clientSecret == null) {
+      throw new IllegalArgumentException("clientSecret can't be null");
+    }
     return new Configuration(clientId, clientSecret);
   }
 
diff --git a/src/main/java/com/amadeus/Configuration.java b/src/main/java/com/amadeus/Configuration.java
index c25bf246..9ac54fca 100644
--- a/src/main/java/com/amadeus/Configuration.java
+++ b/src/main/java/com/amadeus/Configuration.java
@@ -2,6 +2,7 @@
 
 import java.util.Map;
 import java.util.logging.Logger;
+
 import lombok.Getter;
 import lombok.Setter;
 import lombok.ToString;
@@ -110,9 +111,9 @@ protected Configuration(String clientId, String clientSecret) {
    * Builds an Amadeus client with the provided credentials.
    *
    * @return an Amadeus client
-   * @throws NullPointerException when a client ID or client secret is missing
+   * @throws IllegalArgumentException when a client ID or client secret is missing
    */
-  public Amadeus build() throws NullPointerException {
+  public Amadeus build() throws IllegalArgumentException {
     return new Amadeus(this);
   }
 
diff --git a/src/test/java/com/amadeus/AmadeusTest.java b/src/test/java/com/amadeus/AmadeusTest.java
index 3695891e..26a1a279 100644
--- a/src/test/java/com/amadeus/AmadeusTest.java
+++ b/src/test/java/com/amadeus/AmadeusTest.java
@@ -20,11 +20,11 @@ public class AmadeusTest {
   }
 
   @Test public void testBuilderWithNullClientId() {
-    assertThrows(NullPointerException.class, () -> Amadeus.builder(null, "secret").build());
+    assertThrows(IllegalArgumentException.class, () -> Amadeus.builder(null, "secret").build());
   }
 
   @Test public void testBuilderWithNullClientSecret() {
-    assertThrows(NullPointerException.class, () -> Amadeus.builder("client", null).build());
+    assertThrows(IllegalArgumentException.class, () -> Amadeus.builder("client", null).build());
   }
 
   @Test public void testBuilderWithEnvironment() {