2 files changed, 2 insertions, 2 deletions

diff --git a/src/wixext/ComPlusExtensionFactory.cs b/src/wixext/ComPlusExtensionFactory.cs
index d9405867..76b51bff 100644
--- a/src/wixext/ComPlusExtensionFactory.cs
+++ b/src/wixext/ComPlusExtensionFactory.cs
@@ -8,7 +8,7 @@ namespace WixToolset.ComPlus
 
     public class ComPlusExtensionFactory : BaseExtensionFactory
     {
-        protected override IEnumerable<Type> ExtensionTypes => new[]
+        protected override IReadOnlyCollection<Type> ExtensionTypes => new[]
         {
             typeof(ComPlusCompiler),
             typeof(ComPlusExtensionData),
diff --git a/src/wixext/ComPlusWindowsInstallerBackendBinderExtension.cs b/src/wixext/ComPlusWindowsInstallerBackendBinderExtension.cs
index 6083c22b..cf226a3d 100644
--- a/src/wixext/ComPlusWindowsInstallerBackendBinderExtension.cs
+++ b/src/wixext/ComPlusWindowsInstallerBackendBinderExtension.cs
@@ -8,6 +8,6 @@ namespace WixToolset.ComPlus
 
     public class ComPlusWindowsInstallerBackendBinderExtension : BaseWindowsInstallerBackendBinderExtension
     {
-        public override IEnumerable<TableDefinition> TableDefinitions => ComPlusTableDefinitions.All;
+        public override IReadOnlyCollection<TableDefinition> TableDefinitions => ComPlusTableDefinitions.All;
     }
 }