diff --git a/src/OrchardCore.Modules/OrchardCore.ContentTypes/Recipes/LuceneRecipeEventHandler.cs b/src/OrchardCore.Modules/OrchardCore.ContentTypes/Recipes/LuceneRecipeEventHandler.cs
index 2993348538d..e72bcc31344 100644
--- a/src/OrchardCore.Modules/OrchardCore.ContentTypes/Recipes/LuceneRecipeEventHandler.cs
+++ b/src/OrchardCore.Modules/OrchardCore.ContentTypes/Recipes/LuceneRecipeEventHandler.cs
@@ -47,10 +47,9 @@ public Task RecipeStepExecutingAsync(RecipeExecutionContext context)
             {
                 if (partDefinition.Settings != null)
                 {
-                    if (partDefinition.Settings.TryGetPropertyValue("ContentIndexSettings", out var existingPartSettings) &&
-                        !partDefinition.Settings.ContainsKey("LuceneContentIndexSettings"))
+                    if (partDefinition.Settings.TryGetPropertyValue("ContentIndexSettings", out var existingPartSettings))
                     {
-                        partDefinition.Settings.Add("LuceneContentIndexSettings", existingPartSettings);
+                        partDefinition.Settings["LuceneContentIndexSettings"] = existingPartSettings;
                     }
 
                     partDefinition.Settings.Remove("ContentIndexSettings");
@@ -59,10 +58,9 @@ public Task RecipeStepExecutingAsync(RecipeExecutionContext context)
                     {
                         if (fieldDefinition.Settings != null)
                         {
-                            if (fieldDefinition.Settings.TryGetPropertyValue("ContentIndexSettings", out var existingFieldSettings) &&
-                                !fieldDefinition.Settings.ContainsKey("LuceneContentIndexSettings"))
+                            if (fieldDefinition.Settings.TryGetPropertyValue("ContentIndexSettings", out var existingFieldSettings))
                             {
-                                fieldDefinition.Settings.Add("LuceneContentIndexSettings", existingFieldSettings);
+                                fieldDefinition.Settings["LuceneContentIndexSettings"] = existingFieldSettings;
                             }
 
                             fieldDefinition.Settings.Remove("ContentIndexSettings");
diff --git a/src/OrchardCore.Modules/OrchardCore.Search.Lucene/Migrations.cs b/src/OrchardCore.Modules/OrchardCore.Search.Lucene/Migrations.cs
index abaded663ab..e3358df23ea 100644
--- a/src/OrchardCore.Modules/OrchardCore.Search.Lucene/Migrations.cs
+++ b/src/OrchardCore.Modules/OrchardCore.Search.Lucene/Migrations.cs
@@ -81,7 +81,7 @@ await _contentDefinitionManager.AlterPartDefinitionAsync(partDefinition.Name, pa
                         jExistingPartSettings.Remove("Tokenized");
                         jExistingPartSettings.Remove("Template");
 
-                        partDefinition.Settings.Add(nameof(LuceneContentIndexSettings), jExistingPartSettings.Clone());
+                        partDefinition.Settings[nameof(LuceneContentIndexSettings)] = jExistingPartSettings.Clone();
                     }
 
                     partDefinition.Settings.Remove("ContentIndexSettings");
@@ -125,8 +125,7 @@ await _contentDefinitionManager.AlterPartDefinitionAsync(partDefinition.Name, pa
                     jExistingPartSettings.Remove("Analyzed");
                     jExistingPartSettings.Remove("Tokenized");
                     jExistingPartSettings.Remove("Template");
-
-                    partDefinition.Settings.Add(nameof(LuceneContentIndexSettings), jExistingPartSettings.Clone());
+                    partDefinition.Settings[nameof(LuceneContentIndexSettings)] = jExistingPartSettings.Clone();
                 }
 
                 partDefinition.Settings.Remove("ContentIndexSettings");
diff --git a/src/OrchardCore/OrchardCore.Search.Elasticsearch.Core/Services/ElasticIndexingService.cs b/src/OrchardCore/OrchardCore.Search.Elasticsearch.Core/Services/ElasticIndexingService.cs
index 56aae46af4c..1e674e3a1e6 100644
--- a/src/OrchardCore/OrchardCore.Search.Elasticsearch.Core/Services/ElasticIndexingService.cs
+++ b/src/OrchardCore/OrchardCore.Search.Elasticsearch.Core/Services/ElasticIndexingService.cs
@@ -297,7 +297,7 @@ await _contentDefinitionManager.AlterPartDefinitionAsync(partDefinition.Name, pa
 
                         if (included is not null && (bool)included)
                         {
-                            partDefinition.Settings.Add(nameof(ElasticContentIndexSettings), JNode.FromObject(existingPartSettings.ToObject<ElasticContentIndexSettings>()));
+                            partDefinition.Settings[nameof(ElasticContentIndexSettings)] = JNode.FromObject(existingPartSettings.ToObject<ElasticContentIndexSettings>());
                         }
                     }
                 });
@@ -316,7 +316,7 @@ await _contentDefinitionManager.AlterPartDefinitionAsync(partDefinition.Name, pa
 
                     if (included != null && (bool)included)
                     {
-                        partDefinition.Settings.Add(nameof(ElasticContentIndexSettings), JNode.FromObject(existingPartSettings.ToObject<ElasticContentIndexSettings>()));
+                        partDefinition.Settings[nameof(ElasticContentIndexSettings)] = JNode.FromObject(existingPartSettings.ToObject<ElasticContentIndexSettings>());
                     }
                 }
 
@@ -328,7 +328,7 @@ await _contentDefinitionManager.AlterPartDefinitionAsync(partDefinition.Name, pa
 
                         if (included != null && (bool)included)
                         {
-                            fieldDefinition.Settings.Add(nameof(ElasticContentIndexSettings), JNode.FromObject(existingFieldSettings.ToObject<ElasticContentIndexSettings>()));
+                            fieldDefinition.Settings[nameof(ElasticContentIndexSettings)] = JNode.FromObject(existingFieldSettings.ToObject<ElasticContentIndexSettings>());
                         }
                     }
                 }