diff --git a/module/zfs/dsl_synctask.c b/module/zfs/dsl_synctask.c
index 409e12884d..86d8ba5595 100644
--- a/module/zfs/dsl_synctask.c
+++ b/module/zfs/dsl_synctask.c
@@ -231,7 +231,7 @@ dsl_sync_task_sync(dsl_sync_task_t *dst, dmu_tx_t *tx)
 		uint64_t used = dsl_dir_phys(dp->dp_root_dir)->dd_used_bytes;
 
 		/* MOS space is triple-dittoed, so we multiply by 3. */
-		if (used + dst->dst_space * 3 > quota) {
+		if (dst->dst_space > 0 && used + dst->dst_space * 3 > quota) {
 			dst->dst_error = SET_ERROR(ENOSPC);
 			if (dst->dst_nowaiter)
 				kmem_free(dst, sizeof (*dst));
diff --git a/module/zfs/zcp_synctask.c b/module/zfs/zcp_synctask.c
index 058910054d..fa12678c95 100644
--- a/module/zfs/zcp_synctask.c
+++ b/module/zfs/zcp_synctask.c
@@ -532,7 +532,7 @@ zcp_synctask_wrapper(lua_State *state)
 		uint64_t used = dsl_dir_phys(dp->dp_root_dir)->dd_used_bytes +
 		    ri->zri_space_used;
 
-		if (used + funcspace > quota) {
+		if (funcspace > 0 && used + funcspace > quota) {
 			err = SET_ERROR(ENOSPC);
 		}
 	}