diff --git a/src/hsm/sc_hsm.c b/src/hsm/sc_hsm.c
index dcd5108..e84a253 100644
--- a/src/hsm/sc_hsm.c
+++ b/src/hsm/sc_hsm.c
@@ -15,6 +15,7 @@
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  */
 
+#include <stdio.h>
 #include "picokeys.h"
 #include "serial.h"
 #include "sc_hsm.h"