2 files changed, 2 insertions, 2 deletions

diff --git a/src/test/Example.Extension/ExamplePreprocessorExtensionAndCommandLine.cs b/src/test/Example.Extension/ExamplePreprocessorExtensionAndCommandLine.cs
index 49f68de5..7244798a 100644
--- a/src/test/Example.Extension/ExamplePreprocessorExtensionAndCommandLine.cs
+++ b/src/test/Example.Extension/ExamplePreprocessorExtensionAndCommandLine.cs
@@ -12,7 +12,7 @@ namespace Example.Extension
     {
         private string exampleValueFromCommandLine;
 
-        public IEnumerable<ExtensionCommandLineSwitch> CommandLineSwitches => throw new NotImplementedException();
+        public IReadOnlyCollection<ExtensionCommandLineSwitch> CommandLineSwitches => throw new NotImplementedException();
 
         public ExamplePreprocessorExtensionAndCommandLine()
         {
diff --git a/src/test/Example.Extension/ExampleWindowsInstallerBackendExtension.cs b/src/test/Example.Extension/ExampleWindowsInstallerBackendExtension.cs
index 87b7855c..afccc56f 100644
--- a/src/test/Example.Extension/ExampleWindowsInstallerBackendExtension.cs
+++ b/src/test/Example.Extension/ExampleWindowsInstallerBackendExtension.cs
@@ -9,7 +9,7 @@ namespace Example.Extension
 
     internal class ExampleWindowsInstallerBackendExtension : BaseWindowsInstallerBackendBinderExtension
     {
-        public override IEnumerable<TableDefinition> TableDefinitions => ExampleTableDefinitions.All;
+        public override IReadOnlyCollection<TableDefinition> TableDefinitions => ExampleTableDefinitions.All;
 
         public override bool TryProcessSymbol(IntermediateSection section, IntermediateSymbol symbol, WindowsInstallerData output, TableDefinitionCollection tableDefinitions)
         {