diff --git a/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/registration/OpenSamlRelyingPartyRegistration.java b/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/registration/OpenSamlRelyingPartyRegistration.java
deleted file mode 100644
index 300fd4d107..0000000000
--- a/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/registration/OpenSamlRelyingPartyRegistration.java
+++ /dev/null
@@ -1,178 +0,0 @@
-/*
- * Copyright 2002-2025 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.springframework.security.saml2.provider.service.registration;
-
-import java.util.Collection;
-import java.util.function.Consumer;
-
-import org.opensaml.saml.saml2.metadata.EntityDescriptor;
-
-import org.springframework.security.saml2.core.Saml2X509Credential;
-
-/**
- * An OpenSAML implementation of {@link RelyingPartyRegistration} that contains OpenSAML
- * objects like {@link EntityDescriptor}.
- *
- * @author Josh Cummings
- * @since 6.1
- * @deprecated This class no longer is needed in order to transmit the
- * {@link EntityDescriptor} to {@link OpenSamlAssertingPartyDetails}. Instead of doing:
- * <pre>
- * 	if (registration instanceof OpenSamlRelyingPartyRegistration openSamlRegistration) {
- * 	    EntityDescriptor descriptor = openSamlRegistration.getAssertingPartyDetails.getEntityDescriptor();
- * 	}
- * </pre> do instead: <pre>
- * 	if (registration.getAssertingPartyMetadata() instanceof openSamlAssertingPartyDetails) {
- * 	    EntityDescriptor descriptor = openSamlAssertingPartyDetails.getEntityDescriptor();
- * 	}
- * </pre>
- */
-@Deprecated
-public final class OpenSamlRelyingPartyRegistration extends RelyingPartyRegistration {
-
-	OpenSamlRelyingPartyRegistration(RelyingPartyRegistration registration) {
-		super(registration.getRegistrationId(), registration.getEntityId(),
-				registration.getAssertionConsumerServiceLocation(), registration.getAssertionConsumerServiceBinding(),
-				registration.getSingleLogoutServiceLocation(), registration.getSingleLogoutServiceResponseLocation(),
-				registration.getSingleLogoutServiceBindings(),
-				(OpenSamlAssertingPartyDetails) registration.getAssertingPartyMetadata(),
-				registration.getNameIdFormat(), registration.isAuthnRequestsSigned(),
-				registration.getDecryptionX509Credentials(), registration.getSigningX509Credentials());
-	}
-
-	/**
-	 * {@inheritDoc}
-	 */
-	@Override
-	public OpenSamlRelyingPartyRegistration.Builder mutate() {
-		OpenSamlAssertingPartyDetails party = (OpenSamlAssertingPartyDetails) getAssertingPartyMetadata();
-		return new Builder(party).registrationId(getRegistrationId())
-			.entityId(getEntityId())
-			.signingX509Credentials((c) -> c.addAll(getSigningX509Credentials()))
-			.decryptionX509Credentials((c) -> c.addAll(getDecryptionX509Credentials()))
-			.assertionConsumerServiceLocation(getAssertionConsumerServiceLocation())
-			.assertionConsumerServiceBinding(getAssertionConsumerServiceBinding())
-			.singleLogoutServiceLocation(getSingleLogoutServiceLocation())
-			.singleLogoutServiceResponseLocation(getSingleLogoutServiceResponseLocation())
-			.singleLogoutServiceBindings((c) -> c.addAll(getSingleLogoutServiceBindings()))
-			.nameIdFormat(getNameIdFormat())
-			.authnRequestsSigned(isAuthnRequestsSigned());
-	}
-
-	/**
-	 * Create a {@link Builder} from an entity descriptor
-	 * @param entityDescriptor the asserting party's {@link EntityDescriptor}
-	 * @return an {@link Builder}
-	 */
-	public static OpenSamlRelyingPartyRegistration.Builder withAssertingPartyEntityDescriptor(
-			EntityDescriptor entityDescriptor) {
-		return new Builder(entityDescriptor);
-	}
-
-	/**
-	 * An OpenSAML version of
-	 * {@link org.springframework.security.saml2.provider.service.registration.RelyingPartyRegistration.AssertingPartyDetails.Builder}
-	 * that contains the underlying {@link EntityDescriptor}
-	 */
-	public static final class Builder extends RelyingPartyRegistration.Builder {
-
-		private Builder(EntityDescriptor entityDescriptor) {
-			super(entityDescriptor.getEntityID(), OpenSamlAssertingPartyDetails.withEntityDescriptor(entityDescriptor));
-		}
-
-		Builder(OpenSamlAssertingPartyDetails details) {
-			super(details.getEntityDescriptor().getEntityID(), details.mutate());
-		}
-
-		@Override
-		public Builder registrationId(String id) {
-			return (Builder) super.registrationId(id);
-		}
-
-		public Builder entityId(String entityId) {
-			return (Builder) super.entityId(entityId);
-		}
-
-		public Builder signingX509Credentials(Consumer<Collection<Saml2X509Credential>> credentialsConsumer) {
-			return (Builder) super.signingX509Credentials(credentialsConsumer);
-		}
-
-		@Override
-		public Builder decryptionX509Credentials(Consumer<Collection<Saml2X509Credential>> credentialsConsumer) {
-			return (Builder) super.decryptionX509Credentials(credentialsConsumer);
-		}
-
-		@Override
-		public Builder assertionConsumerServiceLocation(String assertionConsumerServiceLocation) {
-			return (Builder) super.assertionConsumerServiceLocation(assertionConsumerServiceLocation);
-		}
-
-		@Override
-		public Builder assertionConsumerServiceBinding(Saml2MessageBinding assertionConsumerServiceBinding) {
-			return (Builder) super.assertionConsumerServiceBinding(assertionConsumerServiceBinding);
-		}
-
-		@Override
-		public Builder singleLogoutServiceBinding(Saml2MessageBinding singleLogoutServiceBinding) {
-			return singleLogoutServiceBindings((saml2MessageBindings) -> {
-				saml2MessageBindings.clear();
-				saml2MessageBindings.add(singleLogoutServiceBinding);
-			});
-		}
-
-		@Override
-		public Builder singleLogoutServiceBindings(Consumer<Collection<Saml2MessageBinding>> bindingsConsumer) {
-			return (Builder) super.singleLogoutServiceBindings(bindingsConsumer);
-		}
-
-		@Override
-		public Builder singleLogoutServiceLocation(String singleLogoutServiceLocation) {
-			return (Builder) super.singleLogoutServiceLocation(singleLogoutServiceLocation);
-		}
-
-		public Builder singleLogoutServiceResponseLocation(String singleLogoutServiceResponseLocation) {
-			return (Builder) super.singleLogoutServiceResponseLocation(singleLogoutServiceResponseLocation);
-		}
-
-		@Override
-		public Builder nameIdFormat(String nameIdFormat) {
-			return (Builder) super.nameIdFormat(nameIdFormat);
-		}
-
-		@Override
-		public Builder authnRequestsSigned(Boolean authnRequestsSigned) {
-			return (Builder) super.authnRequestsSigned(authnRequestsSigned);
-		}
-
-		@Override
-		public Builder assertingPartyMetadata(Consumer<AssertingPartyMetadata.Builder<?>> assertingPartyMetadata) {
-			return (Builder) super.assertingPartyMetadata(assertingPartyMetadata);
-		}
-
-		/**
-		 * Build an {@link OpenSamlRelyingPartyRegistration}
-		 * {@link org.springframework.security.saml2.provider.service.registration.OpenSamlRelyingPartyRegistration}
-		 * @return an {@link OpenSamlRelyingPartyRegistration}
-		 */
-		@Override
-		public OpenSamlRelyingPartyRegistration build() {
-			return new OpenSamlRelyingPartyRegistration(super.build());
-		}
-
-	}
-
-}
diff --git a/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/registration/RelyingPartyRegistrations.java b/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/registration/RelyingPartyRegistrations.java
index 8c72db6f9c..f6d0979f64 100644
--- a/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/registration/RelyingPartyRegistrations.java
+++ b/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/registration/RelyingPartyRegistrations.java
@@ -221,7 +221,7 @@ public final class RelyingPartyRegistrations {
 				OpenSamlAssertingPartyDetails assertingParty = OpenSamlAssertingPartyDetails
 					.withEntityDescriptor(descriptor)
 					.build();
-				builders.add(new OpenSamlRelyingPartyRegistration.Builder(assertingParty));
+				builders.add(RelyingPartyRegistration.withAssertingPartyMetadata(assertingParty));
 			}
 		}
 		if (builders.isEmpty()) {
diff --git a/saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/registration/RelyingPartyRegistrationsTests.java b/saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/registration/RelyingPartyRegistrationsTests.java
index d3b2ce27f3..1b7c1eb575 100644
--- a/saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/registration/RelyingPartyRegistrationsTests.java
+++ b/saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/registration/RelyingPartyRegistrationsTests.java
@@ -253,8 +253,7 @@ public class RelyingPartyRegistrationsTests {
 	}
 
 	@Test
-	public void fromMetadataLocationWhenResolvableThenUsesEntityIdAndOpenSamlRelyingPartyRegistration()
-			throws Exception {
+	public void fromMetadataLocationWhenResolvableThenUsesEntityIdAndOpenSamlAssertingPartyDetails() throws Exception {
 		try (MockWebServer server = new MockWebServer()) {
 			server.enqueue(new MockResponse().setBody(this.metadata).setResponseCode(200));
 			RelyingPartyRegistration registration = RelyingPartyRegistrations
@@ -263,7 +262,7 @@ public class RelyingPartyRegistrationsTests {
 				.build();
 			AssertingPartyMetadata details = registration.getAssertingPartyMetadata();
 			assertThat(registration.getRegistrationId()).isEqualTo(details.getEntityId());
-			assertThat(registration).isInstanceOf(OpenSamlRelyingPartyRegistration.class);
+			assertThat(details).isInstanceOf(OpenSamlAssertingPartyDetails.class);
 		}
 	}