diff --git a/app/portainer/helpers/stackHelper.js b/app/portainer/helpers/stackHelper.js
index bfaf24b9f..63e959e84 100644
--- a/app/portainer/helpers/stackHelper.js
+++ b/app/portainer/helpers/stackHelper.js
@@ -23,28 +23,45 @@ angular.module('portainer.app').factory('StackHelper', [
       );
     }
 
-    helper.validateYAML = function (yaml, containerNames) {
-      let yamlObject;
-
-      try {
-        yamlObject = YAML.parse(yaml);
-      } catch (err) {
-        return 'There is an error in the yaml syntax: ' + err;
-      }
-
-      const names = _.uniq(GenericHelper.findDeepAll(yamlObject, 'container_name'));
-      const duplicateContainers = _.intersection(containerNames, names);
-
-      if (duplicateContainers.length === 0) return;
-
-      return (
-        (duplicateContainers.length === 1 ? 'This container name is' : 'These container names are') +
-        ' already used by another container running in this environment: ' +
-        _.join(duplicateContainers, ', ') +
-        '.'
-      );
-    };
+    helper.validateYAML = validateYAML;
 
     return helper;
   },
 ]);
+
+function validateYAML(yaml, containerNames, originalContainersNames = []) {
+  let yamlObject;
+
+  try {
+    yamlObject = YAML.parse(yaml);
+  } catch (err) {
+    return 'There is an error in the yaml syntax: ' + err;
+  }
+
+  const names = _.uniq(GenericHelper.findDeepAll(yamlObject, 'container_name'));
+
+  const duplicateContainers = _.intersection(_.difference(containerNames, originalContainersNames), names);
+
+  if (duplicateContainers.length === 0) {
+    return '';
+  }
+
+  return (
+    (duplicateContainers.length === 1 ? 'This container name is' : 'These container names are') +
+    ' already used by another container running in this environment: ' +
+    _.join(duplicateContainers, ', ') +
+    '.'
+  );
+}
+
+export function extractContainerNames(yaml = '') {
+  let yamlObject;
+
+  try {
+    yamlObject = YAML.parse(yaml);
+  } catch (err) {
+    return [];
+  }
+
+  return _.uniq(GenericHelper.findDeepAll(yamlObject, 'container_name'));
+}
diff --git a/app/portainer/views/stacks/edit/stack.html b/app/portainer/views/stacks/edit/stack.html
index 5af957241..adfeb9d02 100644
--- a/app/portainer/views/stacks/edit/stack.html
+++ b/app/portainer/views/stacks/edit/stack.html
@@ -141,6 +141,9 @@
                 <span class="col-sm-12 text-muted small">
                   You can get more information about Compose file format in the <a href="https://docs.docker.com/compose/compose-file/" target="_blank">official documentation</a>.
                 </span>
+                <div class="col-sm-12" ng-if="state.yamlError">
+                  <span class="text-danger small">{{ state.yamlError }}</span>
+                </div>
               </div>
               <div class="form-group">
                 <div class="col-sm-12">
diff --git a/app/portainer/views/stacks/edit/stackController.js b/app/portainer/views/stacks/edit/stackController.js
index 6dc2117f2..cb9dffac6 100644
--- a/app/portainer/views/stacks/edit/stackController.js
+++ b/app/portainer/views/stacks/edit/stackController.js
@@ -3,6 +3,7 @@ import { AccessControlFormData } from 'Portainer/components/accessControlForm/po
 import { FeatureId } from 'Portainer/feature-flags/enums';
 import { getEnvironments } from '@/react/portainer/environments/environment.service';
 import { StackStatus, StackType } from '@/react/docker/stacks/types';
+import { extractContainerNames } from '@/portainer/helpers/stackHelper';
 
 angular.module('portainer.app').controller('StackController', [
   '$async',
@@ -275,7 +276,7 @@ angular.module('portainer.app').controller('StackController', [
       if ($scope.stackFileContent.replace(/(\r\n|\n|\r)/gm, '') !== cm.getValue().replace(/(\r\n|\n|\r)/gm, '')) {
         $scope.state.isEditorDirty = true;
         $scope.stackFileContent = cm.getValue();
-        $scope.state.yamlError = StackHelper.validateYAML($scope.stackFileContent, $scope.containerNames);
+        $scope.state.yamlError = StackHelper.validateYAML($scope.stackFileContent, $scope.containerNames, $scope.state.originalContainerNames);
       }
     };
 
@@ -365,8 +366,9 @@ angular.module('portainer.app').controller('StackController', [
             if (isSwarm && $scope.stack.Status === StackStatus.Active) {
               assignSwarmStackResources(data.resources, agentProxy);
             }
+            $scope.state.originalContainerNames = extractContainerNames($scope.stackFileContent);
 
-            $scope.state.yamlError = StackHelper.validateYAML($scope.stackFileContent, $scope.containerNames);
+            $scope.state.yamlError = StackHelper.validateYAML($scope.stackFileContent, $scope.containerNames, $scope.state.originalContainerNames);
           })
           .catch(function error(err) {
             Notifications.error('Failure', err, 'Unable to retrieve stack details');