diff --git a/compiler-rt/lib/scudo/standalone/tsd_exclusive.h b/compiler-rt/lib/scudo/standalone/tsd_exclusive.h
--- a/compiler-rt/lib/scudo/standalone/tsd_exclusive.h
+++ b/compiler-rt/lib/scudo/standalone/tsd_exclusive.h
@@ -15,7 +15,7 @@
 
 struct ThreadState {
   bool DisableMemInit : 1;
-  enum {
+  enum : unsigned {
     NotInitialized = 0,
     Initialized,
     TornDown,