diff --git a/app/models/client.rb b/app/models/client.rb
index 8dde180..9a04d51 100644
--- a/app/models/client.rb
+++ b/app/models/client.rb
@@ -3,8 +3,8 @@ class Client < ApplicationRecord
   has_many :owner_subprojects, class_name: 'Subproject', foreign_key: 'owner_id'
   has_many :builder_subprojects, class_name: 'Subproject', foreign_key: 'builder_id'
 
-  validates :company_name, :firstname, :lastname, presence: true
-  validates :email, presence: true, uniqueness: true
+  validates :company_name, :firstname, :lastname, :email, presence: true
+  validates :email, uniqueness: true
 
   def referenced_count
     owner_subprojects.count + builder_subprojects.count + client_subprojects.count
diff --git a/app/models/subproject.rb b/app/models/subproject.rb
index c943d2d..8b17504 100644
--- a/app/models/subproject.rb
+++ b/app/models/subproject.rb
@@ -14,6 +14,8 @@ class Subproject < ApplicationRecord
   validate :owner_presence_check
   validate :builder_presence_check
 
+  validates_associated :client, :owner, :builder
+
   def client_attributes=(attributes)
     self.client = Client.find_or_initialize_by(email: attributes[:email])
     self.client.assign_attributes(attributes)