diff --git a/web/src/main/java/org/springframework/security/web/authentication/preauth/PreAuthenticatedAuthenticationProvider.java b/web/src/main/java/org/springframework/security/web/authentication/preauth/PreAuthenticatedAuthenticationProvider.java
index 6c767b892e..945a5a6d68 100644
--- a/web/src/main/java/org/springframework/security/web/authentication/preauth/PreAuthenticatedAuthenticationProvider.java
+++ b/web/src/main/java/org/springframework/security/web/authentication/preauth/PreAuthenticatedAuthenticationProvider.java
@@ -157,6 +157,7 @@ public class PreAuthenticatedAuthenticationProvider implements AuthenticationPro
 	 * @param grantedAuthoritySupplier the supplier that grants authorities
 	 */
 	public void setGrantedAuthoritySupplier(Supplier<Collection<GrantedAuthority>> grantedAuthoritySupplier) {
+		Assert.notNull(grantedAuthoritySupplier, "grantedAuthoritySupplier cannot be null");
 		this.grantedAuthoritySupplier = grantedAuthoritySupplier;
 	}