diff --git a/services/src/main/java/org/keycloak/authentication/authenticators/directgrant/ValidateUsername.java b/services/src/main/java/org/keycloak/authentication/authenticators/directgrant/ValidateUsername.java
index 6f19366152..c11c594269 100755
--- a/services/src/main/java/org/keycloak/authentication/authenticators/directgrant/ValidateUsername.java
+++ b/services/src/main/java/org/keycloak/authentication/authenticators/directgrant/ValidateUsername.java
@@ -69,7 +69,7 @@ public class ValidateUsername extends AbstractDirectGrantAuthenticator {
 
 
         if (user == null) {
-            context.getEvent().error(Errors.INVALID_USER_CREDENTIALS);
+            context.getEvent().error(Errors.USER_NOT_FOUND);
             Response challengeResponse = errorResponse(Response.Status.UNAUTHORIZED.getStatusCode(), "invalid_grant", "Invalid user credentials");
             context.failure(AuthenticationFlowError.INVALID_USER, challengeResponse);
             return;
diff --git a/testsuite/integration-arquillian/tests/base/src/test/java/org/keycloak/testsuite/oauth/ResourceOwnerPasswordCredentialsGrantTest.java b/testsuite/integration-arquillian/tests/base/src/test/java/org/keycloak/testsuite/oauth/ResourceOwnerPasswordCredentialsGrantTest.java
index 9c5eb20297..ceabb41484 100755
--- a/testsuite/integration-arquillian/tests/base/src/test/java/org/keycloak/testsuite/oauth/ResourceOwnerPasswordCredentialsGrantTest.java
+++ b/testsuite/integration-arquillian/tests/base/src/test/java/org/keycloak/testsuite/oauth/ResourceOwnerPasswordCredentialsGrantTest.java
@@ -600,7 +600,7 @@ public class ResourceOwnerPasswordCredentialsGrantTest extends AbstractKeycloakT
                 .removeDetail(Details.CODE_ID)
                 .removeDetail(Details.REDIRECT_URI)
                 .removeDetail(Details.CONSENT)
-                .error(Errors.INVALID_USER_CREDENTIALS)
+                .error(Errors.USER_NOT_FOUND)
                 .assertEvent();
     }