diff --git a/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/authentication/SimpleSaml2AuthenticatedPrincipal.java b/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/authentication/DefaultSaml2AuthenticatedPrincipal.java
similarity index 76%
rename from saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/authentication/SimpleSaml2AuthenticatedPrincipal.java
rename to saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/authentication/DefaultSaml2AuthenticatedPrincipal.java
index d926d9c5bc..b474c20aed 100644
--- a/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/authentication/SimpleSaml2AuthenticatedPrincipal.java
+++ b/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/authentication/DefaultSaml2AuthenticatedPrincipal.java
@@ -16,6 +16,8 @@
 
 package org.springframework.security.saml2.provider.service.authentication;
 
+import org.springframework.util.Assert;
+
 import java.io.Serializable;
 import java.util.List;
 import java.util.Map;
@@ -24,14 +26,17 @@ import java.util.Map;
  * Default implementation of a {@link Saml2AuthenticatedPrincipal}.
  *
  * @author Clement Stoquart
- * @since 5.2.2
+ * @since 5.4
  */
-class SimpleSaml2AuthenticatedPrincipal implements Saml2AuthenticatedPrincipal, Serializable {
+public class DefaultSaml2AuthenticatedPrincipal implements Saml2AuthenticatedPrincipal, Serializable {
 
 	private final String name;
 	private final Map<String, List<Object>> attributes;
 
-	SimpleSaml2AuthenticatedPrincipal(String name, Map<String, List<Object>> attributes) {
+	public DefaultSaml2AuthenticatedPrincipal(String name, Map<String, List<Object>> attributes) {
+		Assert.notNull(name, "name cannot be null");
+		Assert.notNull(attributes, "attributes cannot be null");
+
 		this.name = name;
 		this.attributes = attributes;
 	}
diff --git a/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/authentication/OpenSamlAuthenticationProvider.java b/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/authentication/OpenSamlAuthenticationProvider.java
index e8ecc5d0d7..edf5917579 100644
--- a/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/authentication/OpenSamlAuthenticationProvider.java
+++ b/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/authentication/OpenSamlAuthenticationProvider.java
@@ -198,7 +198,7 @@ public final class OpenSamlAuthenticationProvider implements AuthenticationProvi
 				String username = assertion.getSubject().getNameID().getValue();
 				Map<String, List<Object>> attributes = getAssertionAttributes(assertion);
 				return new Saml2Authentication(
-						new SimpleSaml2AuthenticatedPrincipal(username, attributes), token.getSaml2Response(),
+						new DefaultSaml2AuthenticatedPrincipal(username, attributes), token.getSaml2Response(),
 						this.authoritiesMapper.mapAuthorities(getAssertionAuthorities(assertion)));
 			};
 
diff --git a/saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/authentication/SimpleSaml2AuthenticatedPrincipalTests.java b/saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/authentication/DefaultSaml2AuthenticatedPrincipalTests.java
similarity index 65%
rename from saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/authentication/SimpleSaml2AuthenticatedPrincipalTests.java
rename to saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/authentication/DefaultSaml2AuthenticatedPrincipalTests.java
index bd937e78f4..0352be6741 100644
--- a/saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/authentication/SimpleSaml2AuthenticatedPrincipalTests.java
+++ b/saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/authentication/DefaultSaml2AuthenticatedPrincipalTests.java
@@ -26,23 +26,40 @@ import java.util.List;
 import java.util.Map;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatCode;
 
-public class SimpleSaml2AuthenticatedPrincipalTests {
+public class DefaultSaml2AuthenticatedPrincipalTests {
 
 	@Test
-	public void createSimpleSaml2AuthenticatedPrincipal() {
+	public void createDefaultSaml2AuthenticatedPrincipal() {
 		Map<String, List<Object>> attributes = new LinkedHashMap<>();
 		attributes.put("email", Arrays.asList("john.doe@example.com", "doe.john@example.com"));
-		SimpleSaml2AuthenticatedPrincipal principal = new SimpleSaml2AuthenticatedPrincipal("user", attributes);
+		DefaultSaml2AuthenticatedPrincipal principal = new DefaultSaml2AuthenticatedPrincipal("user", attributes);
 		assertThat(principal.getName()).isEqualTo("user");
 		assertThat(principal.getAttributes()).isEqualTo(attributes);
 	}
 
+	@Test
+	public void createDefaultSaml2AuthenticatedPrincipalWhenNameNullThenException() {
+		Map<String, List<Object>> attributes = new LinkedHashMap<>();
+		attributes.put("email", Arrays.asList("john.doe@example.com", "doe.john@example.com"));
+		assertThatCode(() -> new DefaultSaml2AuthenticatedPrincipal(null, attributes))
+				.isInstanceOf(IllegalArgumentException.class)
+				.hasMessageContaining("name cannot be null");
+	}
+
+	@Test
+	public void createDefaultSaml2AuthenticatedPrincipalWhenAttributesNullThenException() {
+		assertThatCode(() -> new DefaultSaml2AuthenticatedPrincipal("user", null))
+				.isInstanceOf(IllegalArgumentException.class)
+				.hasMessageContaining("attributes cannot be null");
+	}
+
 	@Test
 	public void getFirstAttributeWhenStringValueThenReturnsValue() {
 		Map<String, List<Object>> attributes = new LinkedHashMap<>();
 		attributes.put("email", Arrays.asList("john.doe@example.com", "doe.john@example.com"));
-		SimpleSaml2AuthenticatedPrincipal principal = new SimpleSaml2AuthenticatedPrincipal("user", attributes);
+		DefaultSaml2AuthenticatedPrincipal principal = new DefaultSaml2AuthenticatedPrincipal("user", attributes);
 		assertThat(principal.<String>getFirstAttribute("email")).isEqualTo(attributes.get("email").get(0));
 	}
 
@@ -50,7 +67,7 @@ public class SimpleSaml2AuthenticatedPrincipalTests {
 	public void getAttributeWhenStringValuesThenReturnsValues() {
 		Map<String, List<Object>> attributes = new LinkedHashMap<>();
 		attributes.put("email", Arrays.asList("john.doe@example.com", "doe.john@example.com"));
-		SimpleSaml2AuthenticatedPrincipal principal = new SimpleSaml2AuthenticatedPrincipal("user", attributes);
+		DefaultSaml2AuthenticatedPrincipal principal = new DefaultSaml2AuthenticatedPrincipal("user", attributes);
 		assertThat(principal.<String>getAttribute("email")).isEqualTo(attributes.get("email"));
 	}
 
@@ -62,7 +79,7 @@ public class SimpleSaml2AuthenticatedPrincipalTests {
 		Map<String, List<Object>> attributes = new LinkedHashMap<>();
 		attributes.put("registration", Arrays.asList(registered, registeredDate));
 
-		SimpleSaml2AuthenticatedPrincipal principal = new SimpleSaml2AuthenticatedPrincipal("user", attributes);
+		DefaultSaml2AuthenticatedPrincipal principal = new DefaultSaml2AuthenticatedPrincipal("user", attributes);
 
 		List<Object> registrationInfo = principal.getAttribute("registration");