diff --git a/src/Umbraco.Core/Cache/PartialViewCacheInvalidators/NoopMemberPartialViewCacheInvalidator.cs b/src/Umbraco.Core/Cache/PartialViewCacheInvalidators/NoopMemberPartialViewCacheInvalidator.cs
new file mode 100644
index 0000000000..3fd366f2c7
--- /dev/null
+++ b/src/Umbraco.Core/Cache/PartialViewCacheInvalidators/NoopMemberPartialViewCacheInvalidator.cs
@@ -0,0 +1,9 @@
+namespace Umbraco.Cms.Core.Cache.PartialViewCacheInvalidators;
+
+internal class NoopMemberPartialViewCacheInvalidator : IMemberPartialViewCacheInvalidator
+{
+    public void ClearPartialViewCacheItems(IEnumerable<int> memberIds)
+    {
+        // No operation performed, this is a no-op implementation.
+    }
+}
diff --git a/src/Umbraco.Core/DependencyInjection/UmbracoBuilder.cs b/src/Umbraco.Core/DependencyInjection/UmbracoBuilder.cs
index 77d814579c..c6802ed29e 100644
--- a/src/Umbraco.Core/DependencyInjection/UmbracoBuilder.cs
+++ b/src/Umbraco.Core/DependencyInjection/UmbracoBuilder.cs
@@ -8,11 +8,13 @@ using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
 using Microsoft.Extensions.Options;
 using Umbraco.Cms.Core.Cache;
+using Umbraco.Cms.Core.Cache.PartialViewCacheInvalidators;
 using Umbraco.Cms.Core.Composing;
 using Umbraco.Cms.Core.Configuration;
 using Umbraco.Cms.Core.Configuration.Models;
 using Umbraco.Cms.Core.Diagnostics;
 using Umbraco.Cms.Core.Dictionary;
+using Umbraco.Cms.Core.DynamicRoot;
 using Umbraco.Cms.Core.Editors;
 using Umbraco.Cms.Core.Events;
 using Umbraco.Cms.Core.Features;
@@ -32,7 +34,6 @@ using Umbraco.Cms.Core.Scoping;
 using Umbraco.Cms.Core.Security;
 using Umbraco.Cms.Core.Services;
 using Umbraco.Cms.Core.Services.ContentTypeEditing;
-using Umbraco.Cms.Core.DynamicRoot;
 using Umbraco.Cms.Core.Preview;
 using Umbraco.Cms.Core.PublishedCache;
 using Umbraco.Cms.Core.PublishedCache.Internal;
@@ -389,6 +390,11 @@ namespace Umbraco.Cms.Core.DependencyInjection
             Services.AddUnique<IDataTypeConfigurationCache, DataTypeConfigurationCache>();
             Services.AddNotificationHandler<DataTypeCacheRefresherNotification, DataTypeConfigurationCacheRefresher>();
 
+            // Partial view cache invalidators (no-op, shipped implementation is added in Umbraco.Web.Website, but we
+            // need this to ensure we have a service registered for this interface even in headless setups).
+            // See: https://github.com/umbraco/Umbraco-CMS/issues/19661
+            Services.AddUnique<IMemberPartialViewCacheInvalidator, NoopMemberPartialViewCacheInvalidator>();
+
             // Two factor providers
             Services.AddUnique<ITwoFactorLoginService, TwoFactorLoginService>();
             Services.AddUnique<IUserTwoFactorLoginService, UserTwoFactorLoginService>();
diff --git a/src/Umbraco.Web.Website/Cache/PartialViewCacheInvalidators/MemberPartialViewCacheInvalidator.cs b/src/Umbraco.Web.Website/Cache/PartialViewCacheInvalidators/MemberPartialViewCacheInvalidator.cs
index 8ee4be4c00..96adf580b6 100644
--- a/src/Umbraco.Web.Website/Cache/PartialViewCacheInvalidators/MemberPartialViewCacheInvalidator.cs
+++ b/src/Umbraco.Web.Website/Cache/PartialViewCacheInvalidators/MemberPartialViewCacheInvalidator.cs
@@ -32,7 +32,7 @@ public class MemberPartialViewCacheInvalidator : IMemberPartialViewCacheInvalida
             _appCaches.RuntimeCache.ClearByRegex($"{CoreCacheHelperExtensions.PartialViewCacheKey}.*-m{memberId}-*");
         }
 
-        // since it is possible to add a cache item linked to members without a member logged in, we should always clear these items.
+        // Since it is possible to add a cache item linked to members without a member logged in, we should always clear these items.
         _appCaches.RuntimeCache.ClearByRegex($"{CoreCacheHelperExtensions.PartialViewCacheKey}.*-m-*");
     }
 }