diff --git a/lib/travis/api/app/endpoint/env_vars.rb b/lib/travis/api/app/endpoint/env_vars.rb
index 0bed10fe..2cbcd56c 100644
--- a/lib/travis/api/app/endpoint/env_vars.rb
+++ b/lib/travis/api/app/endpoint/env_vars.rb
@@ -13,7 +13,7 @@ class Travis::Api::App
         record.update(data)
 
         # if we update from private to public reset value
-        if !previously_public && record.public?
+        if !previously_public && record.public? && data['value'].nil?
           record.value = nil
         end
 
diff --git a/spec/integration/v2/settings/env_vars_spec.rb b/spec/integration/v2/settings/env_vars_spec.rb
index 5c486f02..c7e2d789 100644
--- a/spec/integration/v2/settings/env_vars_spec.rb
+++ b/spec/integration/v2/settings/env_vars_spec.rb
@@ -83,6 +83,20 @@ describe Travis::Api::App::SettingsEndpoint do
     end
 
     describe 'PATCH /settings/env_vars/:id' do
+      it 'resets value if private key is made public unless new value is provided' do
+        settings = repo.settings
+        env_var = settings.env_vars.create(name: 'FOO', value: 'bar')
+        settings.save
+
+        body = { env_var: { public: true, value: 'a new value' } }.to_json
+        response = patch "/settings/env_vars/#{env_var.id}?repository_id=#{repo.id}", body, headers
+        json = JSON.parse(response.body)
+        json['env_var']['value'].should == 'a new value'
+
+        updated_env_var = repo.reload.settings.env_vars.find(env_var.id)
+        updated_env_var.value.decrypt.should == 'a new value'
+      end
+
       it 'resets value if private key is made public' do
         settings = repo.settings
         env_var = settings.env_vars.create(name: 'FOO', value: 'bar')