diff --git a/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/CacheSaml2AuthenticationRequestRepository.java b/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/CacheSaml2AuthenticationRequestRepository.java
index c53f7004d4d..c16f8f4c721 100644
--- a/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/CacheSaml2AuthenticationRequestRepository.java
+++ b/saml2/saml2-service-provider/src/main/java/org/springframework/security/saml2/provider/service/web/CacheSaml2AuthenticationRequestRepository.java
@@ -54,7 +54,7 @@ public final class CacheSaml2AuthenticationRequestRepository
 	public void saveAuthenticationRequest(AbstractSaml2AuthenticationRequest authenticationRequest,
 			HttpServletRequest request, HttpServletResponse response) {
 		Assert.notNull(authenticationRequest, "authenticationRequest must not be null");
-		String relayState = request.getParameter(Saml2ParameterNames.RELAY_STATE);
+		String relayState = authenticationRequest.getRelayState();
 		Assert.notNull(relayState, "relayState must not be null");
 		this.cache.put(relayState, authenticationRequest);
 	}
diff --git a/saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/web/CacheSaml2AuthenticationRequestRepositoryTests.java b/saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/web/CacheSaml2AuthenticationRequestRepositoryTests.java
index 10a77bdef6d..b4ee3b450bc 100644
--- a/saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/web/CacheSaml2AuthenticationRequestRepositoryTests.java
+++ b/saml2/saml2-service-provider/src/test/java/org/springframework/security/saml2/provider/service/web/CacheSaml2AuthenticationRequestRepositoryTests.java
@@ -42,15 +42,25 @@ class CacheSaml2AuthenticationRequestRepositoryTests {
 
 	@Test
 	void loadAuthenticationRequestWhenCachedThenReturns() {
-		MockHttpServletRequest request = new MockHttpServletRequest();
-		request.setParameter(Saml2ParameterNames.RELAY_STATE, "test");
 		Saml2PostAuthenticationRequest authenticationRequest = TestSaml2PostAuthenticationRequests.create();
+		String relayState = authenticationRequest.getRelayState();
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setParameter(Saml2ParameterNames.RELAY_STATE, relayState);
 		this.repository.saveAuthenticationRequest(authenticationRequest, request, null);
 		assertThat(this.repository.loadAuthenticationRequest(request)).isEqualTo(authenticationRequest);
 		this.repository.removeAuthenticationRequest(request, null);
 		assertThat(this.repository.loadAuthenticationRequest(request)).isNull();
 	}
 
+	@Test
+	void saveAuthenticationRequestWhenRelayStateOnlyInAuthenticationRequestThenSaves() {
+		Saml2PostAuthenticationRequest authenticationRequest = TestSaml2PostAuthenticationRequests.create();
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		this.repository.saveAuthenticationRequest(authenticationRequest, request, null);
+		request.setParameter(Saml2ParameterNames.RELAY_STATE, authenticationRequest.getRelayState());
+		assertThat(this.repository.loadAuthenticationRequest(request)).isEqualTo(authenticationRequest);
+	}
+
 	@Test
 	void loadAuthenticationRequestWhenNoRelayStateThenException() {
 		MockHttpServletRequest request = new MockHttpServletRequest();
@@ -77,15 +87,16 @@ void repositoryWhenCustomCacheThenUses() {
 		CacheSaml2AuthenticationRequestRepository repository = new CacheSaml2AuthenticationRequestRepository();
 		Cache cache = spy(new ConcurrentMapCache("requests"));
 		repository.setCache(cache);
-		MockHttpServletRequest request = new MockHttpServletRequest();
-		request.setParameter(Saml2ParameterNames.RELAY_STATE, "test");
 		Saml2PostAuthenticationRequest authenticationRequest = TestSaml2PostAuthenticationRequests.create();
+		String relayState = authenticationRequest.getRelayState();
+		MockHttpServletRequest request = new MockHttpServletRequest();
+		request.setParameter(Saml2ParameterNames.RELAY_STATE, relayState);
 		repository.saveAuthenticationRequest(authenticationRequest, request, null);
-		verify(cache).put(eq("test"), any());
+		verify(cache).put(eq(relayState), any());
 		repository.loadAuthenticationRequest(request);
-		verify(cache).get("test", AbstractSaml2AuthenticationRequest.class);
+		verify(cache).get(relayState, AbstractSaml2AuthenticationRequest.class);
 		repository.removeAuthenticationRequest(request, null);
-		verify(cache).evict("test");
+		verify(cache).evict(relayState);
 	}
 
 }