diff --git a/tests/check_reduction.c b/tests/check_reduction.c
index ca52946fa5..1f10878523 100644
--- a/tests/check_reduction.c
+++ b/tests/check_reduction.c
@@ -7,6 +7,7 @@
 #include <stdint.h>
 #include <stddef.h>
 #include <stdlib.h>
+#include <math.h>
 
 
 extern void *ctx;