diff --git a/include/sys/ddt.h b/include/sys/ddt.h
index bb7931636..68b8c453a 100644
--- a/include/sys/ddt.h
+++ b/include/sys/ddt.h
@@ -175,7 +175,7 @@ typedef struct ddt_ops {
 	int (*ddt_op_count)(objset_t *os, uint64_t object, uint64_t *count);
 } ddt_ops_t;
 
-#define	DDT_NAMELEN	102
+#define	DDT_NAMELEN	107
 
 extern void ddt_object_name(ddt_t *ddt, enum ddt_type type,
     enum ddt_class class, char *name);
diff --git a/lib/libspl/include/sys/mnttab.h b/lib/libspl/include/sys/mnttab.h
index 026a8fa7b..dd9eb9b16 100644
--- a/lib/libspl/include/sys/mnttab.h
+++ b/lib/libspl/include/sys/mnttab.h
@@ -39,7 +39,7 @@
 #endif /* MNTTAB */
 
 #define	MNTTAB		"/proc/self/mounts"
-#define	MNT_LINE_MAX	4096
+#define	MNT_LINE_MAX	4108
 
 #define	MNT_TOOLONG	1	/* entry exceeds MNT_LINE_MAX */
 #define	MNT_TOOMANY	2	/* too many fields in line */