diff --git a/include/sys/dmu_send.h b/include/sys/dmu_send.h
index 061b81532f..75d8568eb5 100644
--- a/include/sys/dmu_send.h
+++ b/include/sys/dmu_send.h
@@ -54,7 +54,7 @@ dmu_send(const char *tosnap, const char *fromsnap, boolean_t embedok,
     const char *redactbook, int outfd, offset_t *off,
     struct dmu_send_outparams *dsop);
 int dmu_send_estimate_fast(struct dsl_dataset *ds, struct dsl_dataset *fromds,
-    zfs_bookmark_phys_t *frombook, boolean_t stream_compressed,
+    zfs_bookmark_phys_t *frombook, boolean_t compressok, boolean_t rawok,
     boolean_t saved, uint64_t *sizep);
 int dmu_send_obj(const char *pool, uint64_t tosnap, uint64_t fromsnap,
     boolean_t embedok, boolean_t large_block_ok, boolean_t compressok,
diff --git a/module/zfs/dmu_send.c b/module/zfs/dmu_send.c
index cb2b62fed3..5197a89f3e 100644
--- a/module/zfs/dmu_send.c
+++ b/module/zfs/dmu_send.c
@@ -3009,16 +3009,21 @@ dmu_adjust_send_estimate_for_indirects(dsl_dataset_t *ds, uint64_t uncompressed,
 
 int
 dmu_send_estimate_fast(dsl_dataset_t *origds, dsl_dataset_t *fromds,
-    zfs_bookmark_phys_t *frombook, boolean_t stream_compressed,
+    zfs_bookmark_phys_t *frombook, boolean_t compressok, boolean_t rawok,
     boolean_t saved, uint64_t *sizep)
 {
 	int err;
 	dsl_dataset_t *ds = origds;
+	ds_hold_flags_t dsflags;
 	uint64_t uncomp, comp;
+	boolean_t owned = B_FALSE;
+	boolean_t stream_compressed = compressok || rawok;
 
 	ASSERT(dsl_pool_config_held(origds->ds_dir->dd_pool));
 	ASSERT(fromds == NULL || frombook == NULL);
 
+	dsflags = (rawok) ? DS_HOLD_FLAG_NONE : DS_HOLD_FLAG_DECRYPT;
+
 	/*
 	 * If this is a saved send we may actually be sending
 	 * from the %recv clone used for resuming.
@@ -3056,10 +3061,22 @@ dmu_send_estimate_fast(dsl_dataset_t *origds, dsl_dataset_t *fromds,
 		}
 	}
 
-	/* tosnap must be a snapshot or the target of a saved send */
-	if (!ds->ds_is_snapshot && ds == origds)
-		return (SET_ERROR(EINVAL));
+	/*
+	 * If we are sending a filesystem or volume, ensure
+	 * that it doesn't change by owning the dataset.
+	 */
+	if (!ds->ds_is_snapshot && ds == origds) {
+		char dsname[ZFS_MAX_DATASET_NAME_LEN];
 
+		dsl_dataset_name(ds, dsname);
+		err = dsl_dataset_own(ds->ds_dir->dd_pool, dsname, dsflags,
+		    FTAG, &ds);
+
+		if (err != 0)
+			return (err);
+
+		owned = B_TRUE;
+	}
 	if (fromds != NULL) {
 		uint64_t used;
 		if (!fromds->ds_is_snapshot) {
@@ -3097,6 +3114,10 @@ dmu_send_estimate_fast(dsl_dataset_t *origds, dsl_dataset_t *fromds,
 out:
 	if (ds != origds)
 		dsl_dataset_rele(ds, FTAG);
+
+	if (owned == B_TRUE)
+		dsl_dataset_disown(ds, dsflags, FTAG);
+
 	return (err);
 }
 
diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c
index 7b527eb75e..9241abc8b9 100644
--- a/module/zfs/zfs_ioctl.c
+++ b/module/zfs/zfs_ioctl.c
@@ -5678,7 +5678,7 @@ zfs_ioc_send(zfs_cmd_t *zc)
 		}
 
 		error = dmu_send_estimate_fast(tosnap, fromsnap, NULL,
-		    compressok || rawok, savedok, &zc->zc_objset_type);
+		    compressok, rawok, savedok, &zc->zc_objset_type);
 
 		if (fromsnap != NULL)
 			dsl_dataset_rele(fromsnap, FTAG);
@@ -6849,7 +6849,7 @@ zfs_ioc_send_space(const char *snapname, nvlist_t *innvl, nvlist_t *outnvl)
 	} else {
 		error = dmu_send_estimate_fast(tosnap, fromsnap,
 		    (from && strchr(fromname, '#') != NULL ? &zbm : NULL),
-		    compressok || rawok, savedok, &space);
+		    compressok, rawok, savedok, &space);
 		space -= resume_bytes;
 		if (fromsnap != NULL)
 			dsl_dataset_rele(fromsnap, FTAG);