diff --git a/core/src/main/java/org/springframework/security/authentication/dao/AbstractUserDetailsAuthenticationProvider.java b/core/src/main/java/org/springframework/security/authentication/dao/AbstractUserDetailsAuthenticationProvider.java
index 966d1781cc..ce1e84fa6a 100644
--- a/core/src/main/java/org/springframework/security/authentication/dao/AbstractUserDetailsAuthenticationProvider.java
+++ b/core/src/main/java/org/springframework/security/authentication/dao/AbstractUserDetailsAuthenticationProvider.java
@@ -16,6 +16,8 @@
 package org.springframework.security.authentication.dao;
 
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.springframework.security.authentication.AccountExpiredException;
 import org.springframework.security.authentication.AuthenticationProvider;
 import org.springframework.security.authentication.BadCredentialsException;
@@ -71,6 +73,9 @@ import org.springframework.util.Assert;
  */
 public abstract class AbstractUserDetailsAuthenticationProvider implements AuthenticationProvider, InitializingBean,
         MessageSourceAware {
+
+    protected final Log logger = LogFactory.getLog(getClass());
+
     //~ Instance fields ================================================================================================
 
     protected MessageSourceAccessor messages = SpringSecurityMessageSource.getAccessor();
@@ -123,6 +128,8 @@ public abstract class AbstractUserDetailsAuthenticationProvider implements Authe
             try {
                 user = retrieveUser(username, (UsernamePasswordAuthenticationToken) authentication);
             } catch (UsernameNotFoundException notFound) {
+                logger.debug("User '" + username + "' not found");
+
                 if (hideUserNotFoundExceptions) {
                     throw new BadCredentialsException(messages.getMessage(
                             "AbstractUserDetailsAuthenticationProvider.badCredentials", "Bad credentials"));
@@ -178,7 +185,7 @@ public abstract class AbstractUserDetailsAuthenticationProvider implements Authe
      * @return the successful authentication token
      */
     protected Authentication createSuccessAuthentication(Object principal, Authentication authentication,
-        UserDetails user) {
+            UserDetails user) {
         // Ensure we return the original credentials the user supplied,
         // so subsequent attempts are successful even with encoded passwords.
         // Also ensure we return the original getDetails(), so that future
@@ -291,16 +298,22 @@ public abstract class AbstractUserDetailsAuthenticationProvider implements Authe
     private class DefaultPreAuthenticationChecks implements UserDetailsChecker {
         public void check(UserDetails user) {
             if (!user.isAccountNonLocked()) {
+                logger.debug("User account is locked");
+
                 throw new LockedException(messages.getMessage("AbstractUserDetailsAuthenticationProvider.locked",
                         "User account is locked"), user);
             }
 
             if (!user.isEnabled()) {
+                logger.debug("User account is disabled");
+
                 throw new DisabledException(messages.getMessage("AbstractUserDetailsAuthenticationProvider.disabled",
                         "User is disabled"), user);
             }
 
             if (!user.isAccountNonExpired()) {
+                logger.debug("User account is expired");
+
                 throw new AccountExpiredException(messages.getMessage("AbstractUserDetailsAuthenticationProvider.expired",
                         "User account has expired"), user);
             }
@@ -310,6 +323,8 @@ public abstract class AbstractUserDetailsAuthenticationProvider implements Authe
     private class DefaultPostAuthenticationChecks implements UserDetailsChecker {
         public void check(UserDetails user) {
             if (!user.isCredentialsNonExpired()) {
+                logger.debug("User account credentials have expired");
+
                 throw new CredentialsExpiredException(messages.getMessage(
                         "AbstractUserDetailsAuthenticationProvider.credentialsExpired",
                         "User credentials have expired"), user);
diff --git a/core/src/main/java/org/springframework/security/authentication/dao/DaoAuthenticationProvider.java b/core/src/main/java/org/springframework/security/authentication/dao/DaoAuthenticationProvider.java
index c713d77e8f..a0fe5eee6d 100644
--- a/core/src/main/java/org/springframework/security/authentication/dao/DaoAuthenticationProvider.java
+++ b/core/src/main/java/org/springframework/security/authentication/dao/DaoAuthenticationProvider.java
@@ -56,6 +56,8 @@ public class DaoAuthenticationProvider extends AbstractUserDetailsAuthentication
         }
 
         if (authentication.getCredentials() == null) {
+            logger.debug("Authentication failed: no credentials provided");
+
             throw new BadCredentialsException(messages.getMessage(
                     "AbstractUserDetailsAuthenticationProvider.badCredentials", "Bad credentials"),
                     includeDetailsObject ? userDetails : null);
@@ -64,6 +66,8 @@ public class DaoAuthenticationProvider extends AbstractUserDetailsAuthentication
         String presentedPassword = authentication.getCredentials().toString();
 
         if (!passwordEncoder.isPasswordValid(userDetails.getPassword(), presentedPassword, salt)) {
+            logger.debug("Authentication failed: password does not match stored value");
+
             throw new BadCredentialsException(messages.getMessage(
                     "AbstractUserDetailsAuthenticationProvider.badCredentials", "Bad credentials"),
                     includeDetailsObject ? userDetails : null);
diff --git a/core/src/main/java/org/springframework/security/core/userdetails/jdbc/JdbcDaoImpl.java b/core/src/main/java/org/springframework/security/core/userdetails/jdbc/JdbcDaoImpl.java
index 032c5990d2..11ad260272 100644
--- a/core/src/main/java/org/springframework/security/core/userdetails/jdbc/JdbcDaoImpl.java
+++ b/core/src/main/java/org/springframework/security/core/userdetails/jdbc/JdbcDaoImpl.java
@@ -152,6 +152,8 @@ public class JdbcDaoImpl extends JdbcDaoSupport implements UserDetailsService {
         List<UserDetails> users = loadUsersByUsername(username);
 
         if (users.size() == 0) {
+            logger.debug("Query returned no results for user '" + username + "'");
+
             throw new UsernameNotFoundException(
                     messages.getMessage("JdbcDaoImpl.notFound", new Object[]{username}, "Username {0} not found"), username);
         }
@@ -173,6 +175,8 @@ public class JdbcDaoImpl extends JdbcDaoSupport implements UserDetailsService {
         addCustomAuthorities(user.getUsername(), dbAuths);
 
         if (dbAuths.size() == 0) {
+            logger.debug("User '" + username + "' has no authorities and will be treated as 'not found'");
+
             throw new UsernameNotFoundException(
                     messages.getMessage("JdbcDaoImpl.noAuthority",
                             new Object[] {username}, "User {0} has no GrantedAuthority"), username);