diff --git a/ext/f2c_lapack/dlamch.c b/ext/f2c_lapack/dlamch.c
index 47130899c..658417e12 100644
--- a/ext/f2c_lapack/dlamch.c
+++ b/ext/f2c_lapack/dlamch.c
@@ -2,6 +2,7 @@
 extern "C" {
 #endif
 #include "f2c.h"
+#include "stdio.h"
 
 doublereal dlamch_(char *cmach)
 {