diff --git a/src/Scrutor/ImplementationTypeSelector.cs b/src/Scrutor/ImplementationTypeSelector.cs
index c6f9e924..7da2c9ae 100644
--- a/src/Scrutor/ImplementationTypeSelector.cs
+++ b/src/Scrutor/ImplementationTypeSelector.cs
@@ -36,7 +36,7 @@ public IServiceTypeSelector AddClasses(bool publicOnly)
 
     public IServiceTypeSelector AddClasses(Action<IImplementationTypeFilter> action)
     {
-        return AddClasses(action, publicOnly: false);
+        return AddClasses(action, publicOnly: true);
     }
 
     public IServiceTypeSelector AddClasses(Action<IImplementationTypeFilter> action, bool publicOnly)