1 files changed, 1 insertions, 1 deletions

diff --git a/src/WixToolset.Core/CompileContext.cs b/src/WixToolset.Core/CompileContext.cs
index 2aeb3998..d84d7aac 100644
--- a/src/WixToolset.Core/CompileContext.cs
+++ b/src/WixToolset.Core/CompileContext.cs
@@ -21,7 +21,7 @@ namespace WixToolset.Core
 
         public string CompilationId { get; set; }
 
-        public IEnumerable<ICompilerExtension> Extensions { get; set; }
+        public IReadOnlyCollection<ICompilerExtension> Extensions { get; set; }
 
         public Platform Platform { get; set; }