diff --git a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/AvailablePluginResource.java b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/AvailablePluginResource.java
index bbd9444f01..7528b43eb2 100644
--- a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/AvailablePluginResource.java
+++ b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/AvailablePluginResource.java
@@ -104,7 +104,13 @@ public class AvailablePluginResource {
   )
   @ApiResponse(responseCode = "401", description = "not authenticated / invalid credentials")
   @ApiResponse(responseCode = "403", description = "not authorized, the current user does not have the \"plugin:read\" privilege")
-  @ApiResponse(responseCode = "404", description = "not found")
+  @ApiResponse(
+    responseCode = "404",
+    description = "not found, no plugin with the specified name found",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    ))
   @ApiResponse(
     responseCode = "500",
     description = "internal server error",
diff --git a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/BranchRootResource.java b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/BranchRootResource.java
index 1a41508e51..b18be9207e 100644
--- a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/BranchRootResource.java
+++ b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/BranchRootResource.java
@@ -82,7 +82,13 @@ public class BranchRootResource {
   @ApiResponse(responseCode = "400", description = "branches not supported for given repository")
   @ApiResponse(responseCode = "401", description = "not authenticated / invalid credentials")
   @ApiResponse(responseCode = "403", description = "not authorized, the current user has no privileges to read the branch")
-  @ApiResponse(responseCode = "404", description = "not found, no branch with the specified name for the repository available or repository not found")
+  @ApiResponse(
+    responseCode = "404",
+    description = "not found, no branch with the specified name for the repository available or repository found",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    ))
   @ApiResponse(
     responseCode = "500",
     description = "internal server error",
@@ -122,7 +128,13 @@ public class BranchRootResource {
   )
   @ApiResponse(responseCode = "401", description = "not authenticated / invalid credentials")
   @ApiResponse(responseCode = "403", description = "not authorized, the current user has no privileges to read the changeset")
-  @ApiResponse(responseCode = "404", description = "not found, no changesets available in the repository")
+  @ApiResponse(
+    responseCode = "404",
+    description = "not found, no changesets available in the repository",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    ))
   @ApiResponse(
     responseCode = "500",
     description = "internal server error",
@@ -137,7 +149,7 @@ public class BranchRootResource {
                           @DefaultValue("0") @QueryParam("page") int page,
                           @DefaultValue("10") @QueryParam("pageSize") int pageSize) throws IOException {
     try (RepositoryService repositoryService = serviceFactory.create(new NamespaceAndName(namespace, name))) {
-      if (!branchExists(branchName, repositoryService)){
+      if (!branchExists(branchName, repositoryService)) {
         throw notFound(entity(Branch.class, branchName).in(Repository.class, namespace + "/" + name));
       }
       Repository repository = repositoryService.getRepository();
diff --git a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/DiffRootResource.java b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/DiffRootResource.java
index 6124cab10b..a41bdb01a3 100644
--- a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/DiffRootResource.java
+++ b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/DiffRootResource.java
@@ -59,7 +59,13 @@ public class DiffRootResource {
   @ApiResponse(responseCode = "400", description = "bad request")
   @ApiResponse(responseCode = "401", description = "not authenticated / invalid credentials")
   @ApiResponse(responseCode = "403", description = "not authorized, the current user has no privileges to read the diff")
-  @ApiResponse(responseCode = "404", description = "not found, no revision with the specified param for the repository available or repository not found")
+  @ApiResponse(
+    responseCode = "404",
+    description = "not found, no revision with the specified param for the repository available or repository found",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    ))
   @ApiResponse(
     responseCode = "500",
     description = "internal server error",
@@ -97,7 +103,13 @@ public class DiffRootResource {
   @ApiResponse(responseCode = "400", description = "bad request")
   @ApiResponse(responseCode = "401", description = "not authenticated / invalid credentials")
   @ApiResponse(responseCode = "403", description = "not authorized, the current user has no privileges to read the diff")
-  @ApiResponse(responseCode = "404", description = "not found, no revision with the specified param for the repository available or repository not found")
+  @ApiResponse(
+    responseCode = "404",
+    description = "not found, no revision with the specified param for the repository available or repository not found",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    ))
   @ApiResponse(
     responseCode = "500",
     description = "internal server error",
diff --git a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/GroupPermissionResource.java b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/GroupPermissionResource.java
index b00719abbe..8e42ef43e3 100644
--- a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/GroupPermissionResource.java
+++ b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/GroupPermissionResource.java
@@ -50,7 +50,13 @@ public class GroupPermissionResource {
     ))
   @ApiResponse(responseCode = "401", description = "not authenticated / invalid credentials")
   @ApiResponse(responseCode = "403", description = "not authorized, the current user has no privileges to read the group")
-  @ApiResponse(responseCode = "404", description = "not found, no group with the specified id/name available")
+  @ApiResponse(
+    responseCode = "404",
+    description = "not found, no group with the specified id/name available",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    ))
   @ApiResponse(
     responseCode = "500",
     description = "internal server error",
@@ -79,7 +85,13 @@ public class GroupPermissionResource {
   @ApiResponse(responseCode = "400", description = "invalid body")
   @ApiResponse(responseCode = "401", description = "not authenticated / invalid credentials")
   @ApiResponse(responseCode = "403", description = "not authorized, the current group does not have the correct privilege")
-  @ApiResponse(responseCode = "404", description = "not found, no group with the specified id/name available")
+  @ApiResponse(
+    responseCode = "404",
+    description = "not found, no group with the specified id/name available",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    ))
   @ApiResponse(
     responseCode = "500",
     description = "internal server error",
diff --git a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/GroupResource.java b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/GroupResource.java
index 0e54d6855d..2a209408db 100644
--- a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/GroupResource.java
+++ b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/GroupResource.java
@@ -56,7 +56,13 @@ public class GroupResource {
   )
   @ApiResponse(responseCode = "401", description = "not authenticated / invalid credentials")
   @ApiResponse(responseCode = "403", description = "not authorized, the current user has no privileges to read the group")
-  @ApiResponse(responseCode = "404", description = "not found, no group with the specified id/name available")
+  @ApiResponse(
+    responseCode = "404",
+    description = "not found, no group with the specified id/name available",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    ))
   @ApiResponse(
     responseCode = "500",
     description = "internal server error",
@@ -110,7 +116,13 @@ public class GroupResource {
   @ApiResponse(responseCode = "400", description = "invalid body, e.g. illegal change of id/group name")
   @ApiResponse(responseCode = "401", description = "not authenticated / invalid credentials")
   @ApiResponse(responseCode = "403", description = "not authorized, the current user does not have the \"group\" privilege")
-  @ApiResponse(responseCode = "404", description = "not found, no group with the specified id/name available")
+  @ApiResponse(
+    responseCode = "404",
+    description = "not found, no group with the specified id/name available",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    ))
   @ApiResponse(
     responseCode = "500",
     description = "internal server error",
diff --git a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/InstalledPluginResource.java b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/InstalledPluginResource.java
index d5c891c2df..a442c70f7e 100644
--- a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/InstalledPluginResource.java
+++ b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/InstalledPluginResource.java
@@ -126,7 +126,13 @@ public class InstalledPluginResource {
   )
   @ApiResponse(responseCode = "401", description = "not authenticated / invalid credentials")
   @ApiResponse(responseCode = "403", description = "not authorized, the current user does not have the \"plugin:read\" privilege")
-  @ApiResponse(responseCode = "404", description = "not found, plugin by given id could not be found")
+  @ApiResponse(
+    responseCode = "404",
+    description = "not found, plugin by given id could not be found",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    ))
   @ApiResponse(
     responseCode = "500",
     description = "internal server error",
diff --git a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/RepositoryTypeResource.java b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/RepositoryTypeResource.java
index fa1c5b66d3..b04ce46d98 100644
--- a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/RepositoryTypeResource.java
+++ b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/RepositoryTypeResource.java
@@ -45,7 +45,13 @@ public class RepositoryTypeResource {
       schema = @Schema(implementation = RepositoryTypeDto.class)
     )
   )
-  @ApiResponse(responseCode = "404", description = "not found, no repository type with the specified name available")
+  @ApiResponse(
+    responseCode = "404",
+    description = "not found, no repository type with the specified name available",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    ))
   @ApiResponse(
     responseCode = "500",
     description = "internal server error",
diff --git a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/UserPermissionResource.java b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/UserPermissionResource.java
index bf8ff4b3c1..5611b32aeb 100644
--- a/scm-webapp/src/main/java/sonia/scm/api/v2/resources/UserPermissionResource.java
+++ b/scm-webapp/src/main/java/sonia/scm/api/v2/resources/UserPermissionResource.java
@@ -87,15 +87,21 @@ public class UserPermissionResource {
   @ApiResponse(responseCode = "400", description = "invalid body")
   @ApiResponse(responseCode = "401", description = "not authenticated / invalid credentials")
   @ApiResponse(responseCode = "403", description = "not authorized, the current user does not have the correct privilege")
-  @ApiResponse(responseCode = "404", description = "not found, no user with the specified id/name available")
   @ApiResponse(
-        responseCode = "500",
-        description = "internal server error",
-        content = @Content(
-          mediaType = VndMediaType.ERROR_TYPE,
-          schema = @Schema(implementation = ErrorDto.class)
-        )
-      )
+    responseCode = "404",
+    description = "not found, no user with the specified id/name available",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    ))
+  @ApiResponse(
+    responseCode = "500",
+    description = "internal server error",
+    content = @Content(
+      mediaType = VndMediaType.ERROR_TYPE,
+      schema = @Schema(implementation = ErrorDto.class)
+    )
+  )
   public Response overwritePermissions(@PathParam("id") String id, @Valid PermissionListDto newPermissions) {
     Collection<PermissionDescriptor> permissionDescriptors = Arrays.stream(newPermissions.getPermissions())
       .map(PermissionDescriptor::new)