diff --git a/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/CallbackTest.java b/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/CallbackTest.java
index 3335d7a..bc92c09 100644
--- a/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/CallbackTest.java
+++ b/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/CallbackTest.java
@@ -1,3 +1,22 @@
+/*
+ * SonarQube :: GitLab Auth Plugin
+ * Copyright (C) 2016-2017 Talanlabs
+ * gabriel.allaigre@talanlabs.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
 package com.talanlabs.sonar.plugins.gitlab.auth;
 
 import com.squareup.okhttp.mockwebserver.MockResponse;
@@ -18,7 +37,7 @@ public class CallbackTest {
     public MockWebServer gitlab = new MockWebServer();
 
     @Test
-    public void testCallback() {
+    public void testCallbackSuccess() {
         GitLabConfiguration configuration = Mockito.mock(GitLabConfiguration.class);
         Mockito.when(configuration.isEnabled()).thenReturn(true);
         Mockito.when(configuration.allowUsersToSignUp()).thenReturn(true);
@@ -36,8 +55,7 @@ public void testCallback() {
         Mockito.when(callbackContext.getRequest()).thenReturn(httpServletRequest);
 
         gitlab.enqueue(new MockResponse().setBody(
-                "{\n" + " \"access_token\": \"de6780bc506a0446309bd9362820ba8aed28aa506c71eedbe1c5c4f9dd350e54\",\n" + " \"token_type\": \"bearer\",\n" + " \"expires_in\": 7200,\n"
-                        + " \"refresh_token\": \"8257e65c97202ed1726cf9571600918f3bffb2544b26e00a61df9897668c33a1\"\n" + "}"));
+                "{\n" + " \"access_token\": \"de6780bc506a0446309bd9362820ba8aed28aa506c71eedbe1c5c4f9dd350e54\",\n" + " \"token_type\": \"bearer\",\n" + " \"expires_in\": 7200,\n" + " \"refresh_token\": \"8257e65c97202ed1726cf9571600918f3bffb2544b26e00a61df9897668c33a1\"\n" + "}"));
         gitlab.enqueue(new MockResponse().setBody("{\"username\":\"toto\", \"name\":\"Toto Toto\",\"email\":\"toto@toto.com\"}"));
 
         gitLabIdentityProvider.callback(callbackContext);
@@ -51,4 +69,31 @@ public void testCallback() {
         Assertions.assertThat(argument.getValue().getEmail()).isEqualTo("toto@toto.com");
         Mockito.verify(callbackContext).redirectToRequestedPage();
     }
+
+    @Test
+    public void testCallbackFail() {
+        GitLabConfiguration configuration = Mockito.mock(GitLabConfiguration.class);
+        Mockito.when(configuration.isEnabled()).thenReturn(true);
+        Mockito.when(configuration.allowUsersToSignUp()).thenReturn(true);
+        Mockito.when(configuration.applicationId()).thenReturn("123");
+        Mockito.when(configuration.secret()).thenReturn("456");
+        Mockito.when(configuration.url()).thenReturn(String.format("http://%s:%d", gitlab.getHostName(), gitlab.getPort()));
+        GitLabIdentityProvider gitLabIdentityProvider = new GitLabIdentityProvider(configuration);
+
+        OAuth2IdentityProvider.CallbackContext callbackContext = Mockito.mock(OAuth2IdentityProvider.CallbackContext.class);
+        Mockito.when(callbackContext.getCallbackUrl()).thenReturn("http://server/callback");
+
+        HttpServletRequest httpServletRequest = Mockito.mock(HttpServletRequest.class);
+        Mockito.when(httpServletRequest.getParameter("code")).thenReturn("789");
+
+        Mockito.when(callbackContext.getRequest()).thenReturn(httpServletRequest);
+
+        gitlab.enqueue(new MockResponse().setBody(
+                "{\n" + " \"access_token\": \"de6780bc506a0446309bd9362820ba8aed28aa506c71eedbe1c5c4f9dd350e54\",\n" + " \"token_type\": \"bearer\",\n" + " \"expires_in\": 7200,\n"
+                        + " \"refresh_token\": \"8257e65c97202ed1726cf9571600918f3bffb2544b26e00a61df9897668c33a1\"\n" + "}"));
+        gitlab.enqueue(new MockResponse().setResponseCode(404).setBody("empty"));
+
+        Assertions.assertThatThrownBy(() -> gitLabIdentityProvider.callback(callbackContext)).isInstanceOf(IllegalStateException.class)
+                .hasMessageContaining("Fail to authenticate the user. Error code is 404, Body of the response is empty");
+    }
 }
diff --git a/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabApiTest.java b/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabApiTest.java
index dd34676..f3a64fc 100644
--- a/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabApiTest.java
+++ b/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabApiTest.java
@@ -1,3 +1,22 @@
+/*
+ * SonarQube :: GitLab Auth Plugin
+ * Copyright (C) 2016-2017 Talanlabs
+ * gabriel.allaigre@talanlabs.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
 package com.talanlabs.sonar.plugins.gitlab.auth;
 
 import com.github.scribejava.core.extractors.JsonTokenExtractor;
diff --git a/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabAuthPluginTest.java b/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabAuthPluginTest.java
index 9e776dd..b5897f8 100644
--- a/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabAuthPluginTest.java
+++ b/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabAuthPluginTest.java
@@ -1,5 +1,5 @@
 /*
- * SonarQube :: GitLab Plugin
+ * SonarQube :: GitLab Auth Plugin
  * Copyright (C) 2016-2017 Talanlabs
  * gabriel.allaigre@talanlabs.com
  *
diff --git a/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabConfigurationTest.java b/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabConfigurationTest.java
index e768309..5444911 100644
--- a/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabConfigurationTest.java
+++ b/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabConfigurationTest.java
@@ -1,5 +1,5 @@
 /*
- * SonarQube :: GitLab Plugin
+ * SonarQube :: GitLab Auth Plugin
  * Copyright (C) 2016-2017 Talanlabs
  * gabriel.allaigre@talanlabs.com
  *
diff --git a/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabIdentityProviderTest.java b/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabIdentityProviderTest.java
index e3697d3..ee4cda8 100644
--- a/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabIdentityProviderTest.java
+++ b/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GitLabIdentityProviderTest.java
@@ -1,3 +1,22 @@
+/*
+ * SonarQube :: GitLab Auth Plugin
+ * Copyright (C) 2016-2017 Talanlabs
+ * gabriel.allaigre@talanlabs.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
 package com.talanlabs.sonar.plugins.gitlab.auth;
 
 import org.assertj.core.api.Assertions;
@@ -25,7 +44,7 @@ public void testFields() {
     }
 
     @Test
-    public void testInit() {
+    public void testInitSuccess() {
         GitLabConfiguration configuration = Mockito.mock(GitLabConfiguration.class);
         Mockito.when(configuration.isEnabled()).thenReturn(true);
         Mockito.when(configuration.allowUsersToSignUp()).thenReturn(true);
@@ -41,4 +60,20 @@ public void testInit() {
 
         Mockito.verify(initContext).redirectTo("http://server/oauth/authorize?client_id=123&redirect_uri=http%3A%2F%2Fserver%2Fcallback&response_type=code&scope=read_user");
     }
+
+    @Test
+    public void testInitFail() {
+        GitLabConfiguration configuration = Mockito.mock(GitLabConfiguration.class);
+        Mockito.when(configuration.isEnabled()).thenReturn(false);
+        Mockito.when(configuration.allowUsersToSignUp()).thenReturn(true);
+        Mockito.when(configuration.applicationId()).thenReturn("123");
+        Mockito.when(configuration.secret()).thenReturn("456");
+        Mockito.when(configuration.url()).thenReturn("http://server");
+        GitLabIdentityProvider gitLabIdentityProvider = new GitLabIdentityProvider(configuration);
+
+        OAuth2IdentityProvider.InitContext initContext = Mockito.mock(OAuth2IdentityProvider.InitContext.class);
+        Mockito.when(initContext.getCallbackUrl()).thenReturn("http://server/callback");
+
+        Assertions.assertThatThrownBy(() -> gitLabIdentityProvider.init(initContext)).isInstanceOf(IllegalStateException.class).hasMessageContaining("GitLab Authentication is disabled");
+    }
 }
diff --git a/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GsonUserTest.java b/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GsonUserTest.java
index 113ee90..db0b906 100644
--- a/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GsonUserTest.java
+++ b/src/test/java/com/talanlabs/sonar/plugins/gitlab/auth/GsonUserTest.java
@@ -1,3 +1,22 @@
+/*
+ * SonarQube :: GitLab Auth Plugin
+ * Copyright (C) 2016-2017 Talanlabs
+ * gabriel.allaigre@talanlabs.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
 package com.talanlabs.sonar.plugins.gitlab.auth;
 
 import org.assertj.core.api.Assertions;