diff --git a/src/tests.c b/src/tests.c
index be34dfadbba..26c894e2e6a 100644
--- a/src/tests.c
+++ b/src/tests.c
@@ -7,6 +7,7 @@
 #endif
 
 #include <assert.h>
+#include <stdio.h>
 
 #include "impl/num.h"
 #include "impl/field.h"