diff --git a/core/src/main/java/org/springframework/security/authentication/AbstractUserDetailsReactiveAuthenticationManager.java b/core/src/main/java/org/springframework/security/authentication/AbstractUserDetailsReactiveAuthenticationManager.java
index 6ad3f35b539..d32f7e6e20c 100644
--- a/core/src/main/java/org/springframework/security/authentication/AbstractUserDetailsReactiveAuthenticationManager.java
+++ b/core/src/main/java/org/springframework/security/authentication/AbstractUserDetailsReactiveAuthenticationManager.java
@@ -55,7 +55,7 @@ public abstract class AbstractUserDetailsReactiveAuthenticationManager implement
 
 	private ReactiveUserDetailsPasswordService userDetailsPasswordService;
 
-	private Scheduler scheduler = Schedulers.newParallel("password-encoder");
+	private Scheduler scheduler = Schedulers.newParallel("password-encoder", Schedulers.DEFAULT_POOL_SIZE, true);
 
 	private UserDetailsChecker preAuthenticationChecks = user -> {
 		if (!user.isAccountNonLocked()) {