diff --git a/sys/cbor/cbor.c b/sys/cbor/cbor.c
index 05a918cd38..ebab47cbee 100644
--- a/sys/cbor/cbor.c
+++ b/sys/cbor/cbor.c
@@ -24,6 +24,9 @@
 #include <stdlib.h>
 #include <string.h>
 
+#ifdef MODULE_CBOR_CTIME
+#include <time.h>
+#endif
 #define ENABLE_DEBUG (0)
 #include "debug.h"