1 files changed, 1 insertions, 0 deletions
diff --git a/util.c b/util.c
index 6db8ddbfbe..8ec0cd60e5 100644
--- a/util.c
+++ b/util.c
@@ -29,6 +29,7 @@
 #include "internal/sanitizers.h"
 #include "internal/util.h"
 #include "ruby/util.h"
+#include "ruby_atomic.h"
 
 const char ruby_hexdigits[] = "0123456789abcdef0123456789ABCDEF";
 #define hexdigit ruby_hexdigits