1 files changed, 1 insertions, 0 deletions
diff --git a/symbol.h b/symbol.h
index 4b5c676d55..45cf1b21c9 100644
--- a/symbol.h
+++ b/symbol.h
@@ -13,6 +13,7 @@
 #define RUBY_SYMBOL_H 1
 
 #include "id.h"
+#include "ruby/encoding.h"
 
 #define DYNAMIC_ID_P(id) (!(id&ID_STATIC_SYM)&&id>tLAST_OP_ID)
 #define STATIC_ID2SYM(id)  (((VALUE)(id)<<RUBY_SPECIAL_SHIFT)|SYMBOL_FLAG)