diff --git a/src/core/lib/flags.c b/src/core/lib/flags.c
index 8fe7c89..e606d9e 100644
--- a/src/core/lib/flags.c
+++ b/src/core/lib/flags.c
@@ -18,7 +18,6 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 #include <why2/flags.h>
 
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>