diff --git a/sys/compat/linuxkpi/common/include/linux/errno.h b/sys/compat/linuxkpi/common/include/linux/errno.h
--- a/sys/compat/linuxkpi/common/include/linux/errno.h
+++ b/sys/compat/linuxkpi/common/include/linux/errno.h
@@ -34,6 +34,7 @@
 #include <sys/errno.h>
 
 #define	EBADRQC		56	/* Bad request code */
+#define	EBADSLT		57	/* Invalid slot */
 
 #define	ECHRNG		EDOM
 #define	ETIME		ETIMEDOUT