diff --git a/app/controllers/projects/environments_controller.rb b/app/controllers/projects/environments_controller.rb
index 5a4adea497b..c342e1c80b0 100644
--- a/app/controllers/projects/environments_controller.rb
+++ b/app/controllers/projects/environments_controller.rb
@@ -221,7 +221,6 @@ class Projects::EnvironmentsController < Projects::ApplicationController
 
   def metrics_params
     return unless Feature.enabled?(:metrics_time_window, project)
-    return unless params[:start].present? || params[:end].present?
 
     params.require([:start, :end])
   end
diff --git a/spec/controllers/projects/environments_controller_spec.rb b/spec/controllers/projects/environments_controller_spec.rb
index cf23d937037..d5eea5b0439 100644
--- a/spec/controllers/projects/environments_controller_spec.rb
+++ b/spec/controllers/projects/environments_controller_spec.rb
@@ -383,6 +383,8 @@ describe Projects::EnvironmentsController do
   end
 
   describe 'GET #additional_metrics' do
+    let(:window_params) { { start: '1554702993.5398998', end: '1554717396.996232' } }
+
     before do
       allow(controller).to receive(:environment).and_return(environment)
     end
@@ -394,7 +396,7 @@ describe Projects::EnvironmentsController do
 
       context 'when requesting metrics as JSON' do
         it 'returns a metrics JSON document' do
-          additional_metrics
+          additional_metrics(window_params)
 
           expect(response).to have_gitlab_http_status(204)
           expect(json_response).to eq({})
@@ -414,23 +416,19 @@ describe Projects::EnvironmentsController do
       end
 
       it 'returns a metrics JSON document' do
-        additional_metrics
+        additional_metrics(window_params)
 
         expect(response).to be_ok
         expect(json_response['success']).to be(true)
         expect(json_response['data']).to eq({})
         expect(json_response['last_update']).to eq(42)
       end
+    end
 
-      context 'when time params are provided' do
-        it 'returns a metrics JSON document' do
-          additional_metrics(start: '1554702993.5398998', end: '1554717396.996232')
-
-          expect(response).to be_ok
-          expect(json_response['success']).to be(true)
-          expect(json_response['data']).to eq({})
-          expect(json_response['last_update']).to eq(42)
-        end
+    context 'when time params are missing' do
+      it 'raises an error when window params are missing' do
+        expect { additional_metrics }
+        .to raise_error(ActionController::ParameterMissing)
       end
     end
 
@@ -450,7 +448,7 @@ describe Projects::EnvironmentsController do
       end
 
       it 'raises an error when start is missing' do
-        expect { additional_metrics(start: '1552647300.651094') }
+        expect { additional_metrics(end: '1552647300.651094') }
           .to raise_error(ActionController::ParameterMissing)
       end