diff --git a/platform/viewer/cypress/integration/common/OHIFCornerstoneToolbar.spec.js b/platform/viewer/cypress/integration/common/OHIFCornerstoneToolbar.spec.js
index 380622430..e07fc1eea 100644
--- a/platform/viewer/cypress/integration/common/OHIFCornerstoneToolbar.spec.js
+++ b/platform/viewer/cypress/integration/common/OHIFCornerstoneToolbar.spec.js
@@ -393,6 +393,20 @@ describe('OHIF Cornerstone Toolbar', () => {
     });
   });
 
+  it('checks if the available viewport was set to active when layout is decreased', () => {
+    cy.setLayout(3, 3);
+
+    // activate the ninth viewport
+    cy.get('[data-cy=viewport-container-8]')
+      .click()
+      .should('have.class', 'active');
+
+    cy.setLayout(1, 1);
+
+    // first viewport should be active
+    cy.get('[data-cy=viewport-container-0]').should('have.class', 'active');
+  });
+
   it('checks if Clear tool will delete all measurements added in the viewport', () => {
     //Add measurements in the viewport
     cy.addLengthMeasurement();
diff --git a/platform/viewer/src/components/ViewportGrid/ViewportPane.js b/platform/viewer/src/components/ViewportGrid/ViewportPane.js
index 0878003eb..62e0c014a 100644
--- a/platform/viewer/src/components/ViewportGrid/ViewportPane.js
+++ b/platform/viewer/src/components/ViewportGrid/ViewportPane.js
@@ -35,6 +35,7 @@ const ViewportPane = function(props) {
         propClassName
       )}
       ref={drop}
+      data-cy={`viewport-container-${viewportIndex}`}
     >
       {children}
     </div>