diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 12cc6278af..6e0d8f30cb 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -11,6 +11,8 @@
 /* finish iseq array */
 #include "insns.inc"
 
+#include <math.h>
+
 /* control stack frame */