diff --git a/source/dyaml/emitter.d b/source/dyaml/emitter.d
index 9ea2f6f..d73e870 100644
--- a/source/dyaml/emitter.d
+++ b/source/dyaml/emitter.d
@@ -1284,7 +1284,7 @@ struct ScalarWriter
         @disable bool opEquals(ref Emitter);
 
         ///Used as "null" UTF-32 character.
-        immutable dcharNone = dchar.max;
+        static immutable dcharNone = dchar.max;
 
         ///Emitter used to emit the scalar.
         Emitter* emitter_;