diff --git a/src/cdi_datetime.c b/src/cdi_datetime.c
index 1b6c2f428220ef7914032f7eed753a61101e865e..b85463627531c57994105d8d7ceee5a9b8929434 100644
--- a/src/cdi_datetime.c
+++ b/src/cdi_datetime.c
@@ -11,6 +11,7 @@
  * next to find out what happened */
 
 #include "cdi_datetime.h"
+#include <stdio.h>
 #include <stdlib.h>
 
 // ==================================================================