diff --git a/oauth2/oauth2-client/src/main/java/org/springframework/security/oauth2/client/oidc/session/InMemoryOidcSessionRegistry.java b/oauth2/oauth2-client/src/main/java/org/springframework/security/oauth2/client/oidc/session/InMemoryOidcSessionRegistry.java
index 13da5be113b..ffcba6a0372 100644
--- a/oauth2/oauth2-client/src/main/java/org/springframework/security/oauth2/client/oidc/session/InMemoryOidcSessionRegistry.java
+++ b/oauth2/oauth2-client/src/main/java/org/springframework/security/oauth2/client/oidc/session/InMemoryOidcSessionRegistry.java
@@ -50,7 +50,7 @@ public void saveSessionInformation(OidcSessionInformation info) {
 	}
 
 	@Override
-	public OidcSessionInformation removeSessionInformation(String clientSessionId) {
+	public @Nullable OidcSessionInformation removeSessionInformation(String clientSessionId) {
 		OidcSessionInformation information = this.sessions.remove(clientSessionId);
 		if (information != null) {
 			this.logger.trace("Removed client session");
diff --git a/oauth2/oauth2-client/src/main/java/org/springframework/security/oauth2/client/oidc/session/OidcSessionRegistry.java b/oauth2/oauth2-client/src/main/java/org/springframework/security/oauth2/client/oidc/session/OidcSessionRegistry.java
index e984dd5eeed..ab0dfee49ae 100644
--- a/oauth2/oauth2-client/src/main/java/org/springframework/security/oauth2/client/oidc/session/OidcSessionRegistry.java
+++ b/oauth2/oauth2-client/src/main/java/org/springframework/security/oauth2/client/oidc/session/OidcSessionRegistry.java
@@ -16,6 +16,8 @@
 
 package org.springframework.security.oauth2.client.oidc.session;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.security.oauth2.client.oidc.authentication.logout.OidcLogoutToken;
 
 /**
@@ -44,7 +46,7 @@ public interface OidcSessionRegistry {
 	 * @param clientSessionId the client session
 	 * @return any found {@link OidcSessionInformation}, could be {@code null}
 	 */
-	OidcSessionInformation removeSessionInformation(String clientSessionId);
+	@Nullable OidcSessionInformation removeSessionInformation(String clientSessionId);
 
 	/**
 	 * Deregister the OIDC Provider sessions referenced by the provided OIDC Logout Token