diff --git a/omr/pattern.h b/omr/pattern.h
index b040497..1b8e0c4 100644
--- a/omr/pattern.h
+++ b/omr/pattern.h
@@ -24,7 +24,6 @@
 
 namespace Ms {
 
-enum class SymId;
 class Sym;
 
 //---------------------------------------------------------