diff --git a/kdc/kdc_locl.h b/kdc/kdc_locl.h
index 129635a9a..03d95903e 100644
--- a/kdc/kdc_locl.h
+++ b/kdc/kdc_locl.h
@@ -10,6 +10,7 @@
 #endif
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <errno.h>
 #include <signal.h>
 #include <fcntl.h>