diff --git a/include/json/value.h b/include/json/value.h
index 988a22c..c2efe95 100644
--- a/include/json/value.h
+++ b/include/json/value.h
@@ -639,7 +639,7 @@ private:
     ObjectValues* map_;
   } value_;
 
-  struct {
+  struct Bits {
     // Really a ValueType, but types should agree for bitfield packing.
     unsigned int value_type_ : 8;
     // Unless allocated_, string_ must be null-terminated.