diff --git a/lib/travis/api/v3/access_control/user.rb b/lib/travis/api/v3/access_control/user.rb
index 181bb399..ecc54315 100644
--- a/lib/travis/api/v3/access_control/user.rb
+++ b/lib/travis/api/v3/access_control/user.rb
@@ -5,6 +5,7 @@ module Travis::API::V3
     attr_reader :user, :permissions
 
     def initialize(user)
+      user         = Models::User.find(user.id) if user.is_a? ::User
       @user        = user
       @permissions = user.permissions.where(user_id: user.id)
       super()
diff --git a/lib/travis/api/v3/models/user.rb b/lib/travis/api/v3/models/user.rb
index 73136efd..c07f3a4b 100644
--- a/lib/travis/api/v3/models/user.rb
+++ b/lib/travis/api/v3/models/user.rb
@@ -1,5 +1,9 @@
 module Travis::API::V3
   class Models::User < Model
-    has_many :emails
+    has_many :memberships,   dependent: :destroy
+    has_many :organizations, through: :memberships
+    has_many :permissions,   dependent: :destroy
+    has_many :repositories,  through: :permissions
+    has_many :emails,        dependent: :destroy
   end
 end
diff --git a/lib/travis/api/v3/queries/build.rb b/lib/travis/api/v3/queries/build.rb
index f227761a..1f97e7c7 100644
--- a/lib/travis/api/v3/queries/build.rb
+++ b/lib/travis/api/v3/queries/build.rb
@@ -4,7 +4,7 @@ module Travis::API::V3
 
     def find
       return Models::Build.find_by_id(id) if id
-      raise WrongParams
+      raise WrongParams, 'missing build.id'.freeze
     end
   end
 end
diff --git a/lib/travis/api/v3/queries/organization.rb b/lib/travis/api/v3/queries/organization.rb
index ae971d7a..8c07c910 100644
--- a/lib/travis/api/v3/queries/organization.rb
+++ b/lib/travis/api/v3/queries/organization.rb
@@ -4,7 +4,7 @@ module Travis::API::V3
 
     def find
       return Models::Organization.find_by_id(id) if id
-      raise WrongParams
+      raise WrongParams, 'missing organization.id'.freeze
     end
   end
 end
diff --git a/lib/travis/api/v3/queries/repository.rb b/lib/travis/api/v3/queries/repository.rb
index 6542c7b9..d8ceaff9 100644
--- a/lib/travis/api/v3/queries/repository.rb
+++ b/lib/travis/api/v3/queries/repository.rb
@@ -4,7 +4,7 @@ module Travis::API::V3
 
     def find
       return Models::Repository.find_by_id(id) if id
-      raise WrongParams
+      raise WrongParams, 'missing repository.id'.freeze
     end
   end
 end
diff --git a/lib/travis/api/v3/query.rb b/lib/travis/api/v3/query.rb
index 3676065f..48989490 100644
--- a/lib/travis/api/v3/query.rb
+++ b/lib/travis/api/v3/query.rb
@@ -46,9 +46,9 @@ module Travis::API::V3
 
     def user_condition(value)
       case value
-      when String  then { login: value    }
-      when Integer then { id:    value    }
-      when ::User  then { id:    value.id }
+      when String       then { login: value    }
+      when Integer      then { id:    value    }
+      when Models::User then { id:    value.id }
       else raise WrongParams
       end
     end