diff --git a/config/src/main/java/org/springframework/security/config/annotation/web/reactive/WebFluxSecurityConfiguration.java b/config/src/main/java/org/springframework/security/config/annotation/web/reactive/WebFluxSecurityConfiguration.java
index 3735734751..563b80038e 100644
--- a/config/src/main/java/org/springframework/security/config/annotation/web/reactive/WebFluxSecurityConfiguration.java
+++ b/config/src/main/java/org/springframework/security/config/annotation/web/reactive/WebFluxSecurityConfiguration.java
@@ -19,12 +19,11 @@
 package org.springframework.security.config.annotation.web.reactive;
 
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.ReactiveAdapterRegistry;
 import org.springframework.security.authentication.ReactiveAuthenticationManager;
-import org.springframework.security.authentication.UserDetailsRepository;
+import org.springframework.security.core.userdetails.UserDetailsRepository;
 import org.springframework.security.authentication.UserDetailsRepositoryAuthenticationManager;
 import org.springframework.security.config.web.server.HttpSecurity;
 import org.springframework.security.web.reactive.result.method.annotation.AuthenticationPrincipalArgumentResolver;
diff --git a/core/src/main/java/org/springframework/security/authentication/UserDetailsRepository.java b/core/src/main/java/org/springframework/security/authentication/UserDetailsRepository.java
deleted file mode 100644
index 5a6d4f4c5f..0000000000
--- a/core/src/main/java/org/springframework/security/authentication/UserDetailsRepository.java
+++ /dev/null
@@ -1,10 +0,0 @@
-package org.springframework.security.authentication;
-
-import org.springframework.security.core.userdetails.UserDetails;
-
-import reactor.core.publisher.Mono;
-
-public interface UserDetailsRepository {
-
-	Mono<UserDetails> findByUsername(String username);
-}
diff --git a/core/src/main/java/org/springframework/security/authentication/UserDetailsRepositoryAuthenticationManager.java b/core/src/main/java/org/springframework/security/authentication/UserDetailsRepositoryAuthenticationManager.java
index 769c78bc24..cbc98b54ee 100644
--- a/core/src/main/java/org/springframework/security/authentication/UserDetailsRepositoryAuthenticationManager.java
+++ b/core/src/main/java/org/springframework/security/authentication/UserDetailsRepositoryAuthenticationManager.java
@@ -20,6 +20,7 @@ package org.springframework.security.authentication;
 
 import org.springframework.security.core.Authentication;
 
+import org.springframework.security.core.userdetails.UserDetailsRepository;
 import org.springframework.util.Assert;
 import reactor.core.publisher.Mono;
 
diff --git a/core/src/main/java/org/springframework/security/authentication/MapUserDetailsRepository.java b/core/src/main/java/org/springframework/security/core/userdetails/MapUserDetailsRepository.java
similarity index 90%
rename from core/src/main/java/org/springframework/security/authentication/MapUserDetailsRepository.java
rename to core/src/main/java/org/springframework/security/core/userdetails/MapUserDetailsRepository.java
index c5bb4a6424..4b85f79a70 100644
--- a/core/src/main/java/org/springframework/security/authentication/MapUserDetailsRepository.java
+++ b/core/src/main/java/org/springframework/security/core/userdetails/MapUserDetailsRepository.java
@@ -16,7 +16,7 @@
  *
  */
 
-package org.springframework.security.authentication;
+package org.springframework.security.core.userdetails;
 
 import java.util.Arrays;
 import java.util.Collection;
@@ -24,9 +24,6 @@ import java.util.Map;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
-import org.springframework.security.core.userdetails.User;
-import org.springframework.security.core.userdetails.UserDetails;
-
 import org.springframework.util.Assert;
 import reactor.core.publisher.Mono;
 
diff --git a/core/src/main/java/org/springframework/security/core/userdetails/UserDetailsRepository.java b/core/src/main/java/org/springframework/security/core/userdetails/UserDetailsRepository.java
new file mode 100644
index 0000000000..0d338e9139
--- /dev/null
+++ b/core/src/main/java/org/springframework/security/core/userdetails/UserDetailsRepository.java
@@ -0,0 +1,28 @@
+/*
+ *
+ *  * Copyright 2002-2017 the original author or authors.
+ *  *
+ *  * Licensed under the Apache License, Version 2.0 (the "License");
+ *  * you may not use this file except in compliance with the License.
+ *  * You may obtain a copy of the License at
+ *  *
+ *  *      http://www.apache.org/licenses/LICENSE-2.0
+ *  *
+ *  * Unless required by applicable law or agreed to in writing, software
+ *  * distributed under the License is distributed on an "AS IS" BASIS,
+ *  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  * See the License for the specific language governing permissions and
+ *  * limitations under the License.
+ *
+ */
+
+package org.springframework.security.core.userdetails;
+
+import org.springframework.security.core.userdetails.UserDetails;
+
+import reactor.core.publisher.Mono;
+
+public interface UserDetailsRepository {
+
+	Mono<UserDetails> findByUsername(String username);
+}
diff --git a/core/src/test/java/org/springframework/security/authentication/UserDetailsRepositoryAuthenticationManagerTests.java b/core/src/test/java/org/springframework/security/authentication/UserDetailsRepositoryAuthenticationManagerTests.java
index 64da95587c..1cdd49adef 100644
--- a/core/src/test/java/org/springframework/security/authentication/UserDetailsRepositoryAuthenticationManagerTests.java
+++ b/core/src/test/java/org/springframework/security/authentication/UserDetailsRepositoryAuthenticationManagerTests.java
@@ -27,6 +27,7 @@ import org.springframework.security.core.Authentication;
 import org.springframework.security.core.authority.AuthorityUtils;
 import org.springframework.security.core.userdetails.User;
 
+import org.springframework.security.core.userdetails.UserDetailsRepository;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 
diff --git a/core/src/test/java/org/springframework/security/authentication/MapUserDetailsRepositoryTests.java b/core/src/test/java/org/springframework/security/core/userdetails/MapUserDetailsRepositoryTests.java
similarity index 70%
rename from core/src/test/java/org/springframework/security/authentication/MapUserDetailsRepositoryTests.java
rename to core/src/test/java/org/springframework/security/core/userdetails/MapUserDetailsRepositoryTests.java
index f3977e21ea..c9bde78956 100644
--- a/core/src/test/java/org/springframework/security/authentication/MapUserDetailsRepositoryTests.java
+++ b/core/src/test/java/org/springframework/security/core/userdetails/MapUserDetailsRepositoryTests.java
@@ -1,19 +1,21 @@
 /*
- * Copyright 2017 the original author or authors.
  *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
+ *  * Copyright 2002-2017 the original author or authors.
+ *  *
+ *  * Licensed under the Apache License, Version 2.0 (the "License");
+ *  * you may not use this file except in compliance with the License.
+ *  * You may obtain a copy of the License at
+ *  *
+ *  *      http://www.apache.org/licenses/LICENSE-2.0
+ *  *
+ *  * Unless required by applicable law or agreed to in writing, software
+ *  * distributed under the License is distributed on an "AS IS" BASIS,
+ *  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  * See the License for the specific language governing permissions and
+ *  * limitations under the License.
  *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
  */
-package org.springframework.security.authentication;
+package org.springframework.security.core.userdetails;
 
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -23,6 +25,7 @@ import java.util.Collection;
 import java.util.Collections;
 
 import org.junit.Test;
+import org.springframework.security.core.userdetails.MapUserDetailsRepository;
 import org.springframework.security.core.userdetails.User;
 import org.springframework.security.core.userdetails.UserDetails;
 
diff --git a/samples/javaconfig/hellowebflux/src/main/java/sample/SecurityConfig.java b/samples/javaconfig/hellowebflux/src/main/java/sample/SecurityConfig.java
index c4a08b9fc5..4558cb60c5 100644
--- a/samples/javaconfig/hellowebflux/src/main/java/sample/SecurityConfig.java
+++ b/samples/javaconfig/hellowebflux/src/main/java/sample/SecurityConfig.java
@@ -19,7 +19,7 @@
 package sample;
 
 import org.springframework.context.annotation.Bean;
-import org.springframework.security.authentication.MapUserDetailsRepository;
+import org.springframework.security.core.userdetails.MapUserDetailsRepository;
 import org.springframework.security.authorization.AuthorizationDecision;
 import org.springframework.security.config.annotation.web.reactive.EnableWebFluxSecurity;
 import org.springframework.security.config.web.server.HttpSecurity;
diff --git a/samples/javaconfig/hellowebfluxfn/src/main/java/sample/SecurityConfig.java b/samples/javaconfig/hellowebfluxfn/src/main/java/sample/SecurityConfig.java
index c4a08b9fc5..4558cb60c5 100644
--- a/samples/javaconfig/hellowebfluxfn/src/main/java/sample/SecurityConfig.java
+++ b/samples/javaconfig/hellowebfluxfn/src/main/java/sample/SecurityConfig.java
@@ -19,7 +19,7 @@
 package sample;
 
 import org.springframework.context.annotation.Bean;
-import org.springframework.security.authentication.MapUserDetailsRepository;
+import org.springframework.security.core.userdetails.MapUserDetailsRepository;
 import org.springframework.security.authorization.AuthorizationDecision;
 import org.springframework.security.config.annotation.web.reactive.EnableWebFluxSecurity;
 import org.springframework.security.config.web.server.HttpSecurity;