1 files changed, 1 insertions, 0 deletions
diff --git a/dln.h b/dln.h
index d98b2607e2..9570de8f15 100644
--- a/dln.h
+++ b/dln.h
@@ -11,6 +11,7 @@
 
 #ifndef DLN_H
 #define DLN_H
+#include "ruby/defines.h"       /* for RUBY_SYMBOL_EXPORT_BEGIN */
 
 #ifdef __cplusplus
 # ifndef  HAVE_PROTOTYPES