Fix build break in CoreRT/ProjectN

1 files changed, 6 insertions, 1 deletions

diff --git a/src/System.Private.CoreLib/shared/System/Diagnostics/Tracing/EventSource.cs b/src/System.Private.CoreLib/shared/System/Diagnostics/Tracing/EventSource.cs
index 10131124f..1f8c0b06a 100644
--- a/src/System.Private.CoreLib/shared/System/Diagnostics/Tracing/EventSource.cs
+++ b/src/System.Private.CoreLib/shared/System/Diagnostics/Tracing/EventSource.cs
@@ -1785,7 +1785,12 @@ namespace System.Diagnostics.Tracing
                     if (dataType.IsEnum())
                     {
                         dataType = Enum.GetUnderlyingType(dataType);
-                        if (Runtime.InteropServices.Marshal.SizeOf(dataType) < sizeof(int))
+#if ES_BUILD_PN
+                        int dataTypeSize = (int)dataType.TypeHandle.ToEETypePtr().ValueTypeSize;
+#else
+                        int dataTypeSize = System.Runtime.InteropServices.Marshal.SizeOf(dataType);
+#endif
+                        if (dataTypeSize < sizeof(int))
                             dataType = typeof(int);
                         goto Again;
                     }