diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c
index 9140c62a62..e5704e258d 100644
--- a/module/zfs/zfs_ioctl.c
+++ b/module/zfs/zfs_ioctl.c
@@ -3906,7 +3906,7 @@ zfs_check_settable(const char *dsname, nvpair_t *pair, cred_t *cr)
 			return (SET_ERROR(EINVAL));
 
 		/* check prop value is enabled in features */
-		feature = zio_checksum_to_feature(intval);
+		feature = zio_checksum_to_feature(intval & ZIO_CHECKSUM_MASK);
 		if (feature == SPA_FEATURE_NONE)
 			break;
 
diff --git a/module/zfs/zio_checksum.c b/module/zfs/zio_checksum.c
index 59871c50ea..d3d2f05a80 100644
--- a/module/zfs/zio_checksum.c
+++ b/module/zfs/zio_checksum.c
@@ -135,9 +135,15 @@ zio_checksum_info_t zio_checksum_table[ZIO_CHECKSUM_FUNCTIONS] = {
 	    ZCHECKSUM_FLAG_NOPWRITE, "edonr"},
 };
 
+/*
+ * The flag corresponding to the "verify" in dedup=[checksum,]verify
+ * must be cleared first, so callers should use ZIO_CHECKSUM_MASK.
+ */
 spa_feature_t
 zio_checksum_to_feature(enum zio_checksum cksum)
 {
+	VERIFY((cksum & ~ZIO_CHECKSUM_MASK) == 0);
+
 	switch (cksum) {
 	case ZIO_CHECKSUM_SHA512:
 		return (SPA_FEATURE_SHA512);