1 files changed, 1 insertions, 0 deletions

diff --git a/bignum.c b/bignum.c
index b322a659ac..809b164ff7 100644
--- a/bignum.c
+++ b/bignum.c
@@ -11,6 +11,7 @@
 
 #include "ruby/ruby.h"
 #include "ruby/util.h"
+#include "internal.h"
 
 #include <math.h>
 #include <float.h>