diff --git a/config/locales/en.yml b/config/locales/en.yml
index 0001f08..dec6e89 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -2,8 +2,10 @@ en:
   activerecord:
     errors:
       messages:
-        cant_to_closed_deliverable: "Can't create a time entry on a closed deliverable"
-        cant_to_closed_contract: "Can't create a time entry on a closed contract"
+        cant_create_time_on_closed_deliverable: "Can't create a time entry on a closed deliverable"
+        cant_create_time_on_closed_contract: "Can't create a time entry on a closed contract"
+        cant_assign_to_closed_deliverable: "Can't assign issue to a closed deliverable"
+        cant_assign_to_locked_deliverable: "Can't assign issue to a locked deliverable"
 
   field_end_date: End Date
   field_executed: Executed
diff --git a/lib/redmine_contracts/patches/issue_patch.rb b/lib/redmine_contracts/patches/issue_patch.rb
index 4df6003..ba9100d 100644
--- a/lib/redmine_contracts/patches/issue_patch.rb
+++ b/lib/redmine_contracts/patches/issue_patch.rb
@@ -15,6 +15,16 @@ module RedmineContracts
           def contract_name
             contract.try(:name)
           end
+
+          validate :validate_deliverable_status
+
+          def validate_deliverable_status
+            if deliverable.present? && changes["deliverable_id"].present?
+              errors.add_to_base(:cant_assign_to_closed_deliverable) if deliverable.closed?
+              errors.add_to_base(:cant_assign_to_locked_deliverable) if deliverable.locked?
+            end
+          end
+
         end
       end
 
diff --git a/lib/redmine_contracts/patches/time_entry_patch.rb b/lib/redmine_contracts/patches/time_entry_patch.rb
index 58f9d69..0a327b2 100644
--- a/lib/redmine_contracts/patches/time_entry_patch.rb
+++ b/lib/redmine_contracts/patches/time_entry_patch.rb
@@ -13,13 +13,13 @@ module RedmineContracts
 
           def validate_deliverable_status
             if issue.present? && issue.deliverable.present?
-              errors.add_to_base(:cant_to_closed_deliverable) if issue.deliverable.closed?
+              errors.add_to_base(:cant_create_time_on_closed_deliverable) if issue.deliverable.closed?
             end
           end
 
           def validate_contract_status
             if issue.present? && issue.deliverable.present? && issue.deliverable.contract.present?
-              errors.add_to_base(:cant_to_closed_contract) if issue.deliverable.contract.closed?
+              errors.add_to_base(:cant_create_time_on_closed_contract) if issue.deliverable.contract.closed?
             end
           end
           
diff --git a/test/integration/redmine_contracts/hooks/controller_issues_edit_before_save.rb b/test/integration/redmine_contracts/hooks/controller_issues_edit_before_save.rb
index 4b475b2..6810379 100644
--- a/test/integration/redmine_contracts/hooks/controller_issues_edit_before_save.rb
+++ b/test/integration/redmine_contracts/hooks/controller_issues_edit_before_save.rb
@@ -24,10 +24,10 @@ class RedmineContracts::Hooks::ControllerIssuesEditBeforeSaveTest < ActionContro
     context "for a new issue" do
       setup do
         visit_project(@project)
-        click_link "New issue"
       end
       
       should "set the issue's deliverable" do
+        click_link "New issue"
         fill_in "Subject", :with => 'Hook test'
         select @deliverable2.title, :from => "Deliverable"
         click_button "Create"
@@ -38,6 +38,38 @@ class RedmineContracts::Hooks::ControllerIssuesEditBeforeSaveTest < ActionContro
 
       end
 
+      should "not allow setting a locked Deliverable" do
+        assert @deliverable2.lock!
+        click_link "New issue"
+
+        fill_in "Subject", :with => 'Hook test'
+        select @deliverable2.title, :from => "Deliverable"
+        assert_no_difference("Issue.count") do
+          click_button "Create"
+
+          assert_response :success
+        end
+        
+        assert_equal nil, Issue.last.deliverable
+        
+      end
+
+      should "not allow setting a closed Deliverable" do
+        assert @deliverable2.close!
+        click_link "New issue"
+
+        fill_in "Subject", :with => 'Hook test'
+        select @deliverable2.title, :from => "Deliverable"
+        assert_no_difference("Issue.count") do
+          click_button "Create"
+
+          assert_response :success
+        end
+        
+        assert_equal nil, Issue.last.deliverable
+        
+      end
+
       context "with no permission to Assign Deliverable" do
         should "not allow setting the Deliverable (force HTTP request)" do
           @role.permissions.delete(:assign_deliverable_to_issue)
@@ -69,6 +101,51 @@ class RedmineContracts::Hooks::ControllerIssuesEditBeforeSaveTest < ActionContro
 
       end
 
+      should "not allow updating to a locked deliverable" do
+        assert @deliverable2.lock!
+        select @deliverable2.title, :from => "Deliverable"
+        click_button "Submit"
+
+        assert_response :success
+
+        @issue.reload
+        assert_equal nil, @issue.deliverable
+
+      end
+
+      should "not allow updating to a closed deliverable" do
+        assert @deliverable2.close!
+        select @deliverable2.title, :from => "Deliverable"
+        click_button "Submit"
+
+        assert_response :success
+
+        @issue.reload
+        assert_equal nil, @issue.deliverable
+
+      end
+
+      should "allow updating an issue, even if the deliverable is locked as long as the deliverable isn't changed" do
+        select @deliverable2.title, :from => "Deliverable"
+        click_button "Submit"
+
+        assert_response :success
+
+        @issue.reload
+        assert_equal @deliverable2, @issue.deliverable
+
+        # Now normal update after locking
+        assert @deliverable2.lock!
+        fill_in "Subject", :with => 'Change subject'
+        click_button "Submit"
+
+        assert_response :success
+        @issue.reload
+        assert_equal "Change subject", @issue.subject
+        assert_equal @deliverable2, @issue.deliverable        
+        
+      end
+
       context "with no permission to Assign Deliverable" do
         should "not allow setting the Deliverable (force HTTP request)" do
           @role.permissions.delete(:assign_deliverable_to_issue)