diff --git a/etc/systemd/system-generators/zfs-mount-generator.c b/etc/systemd/system-generators/zfs-mount-generator.c
index b07574e72a..ab5dc4d78d 100644
--- a/etc/systemd/system-generators/zfs-mount-generator.c
+++ b/etc/systemd/system-generators/zfs-mount-generator.c
@@ -224,9 +224,10 @@ line_worker(char *line, const char *cachefile)
 	const char *p_systemd_ignore            = strtok_r(NULL, "\t", &toktmp) ?: "-";
 	/* END CSTYLED */
 
-	const char *pool = dataset;
-	if ((toktmp = strchr(pool, '/')) != NULL)
-		pool = strndupa(pool, toktmp - pool);
+	size_t pool_len = strlen(dataset);
+	if ((toktmp = strchr(dataset, '/')) != NULL)
+		pool_len = toktmp - dataset;
+	const char *pool = *(tofree++) = strndup(dataset, pool_len);
 
 	if (p_nbmand == NULL) {
 		fprintf(stderr, PROGNAME "[%d]: %s: not enough tokens!\n",
@@ -734,7 +735,7 @@ end:
 	if (tofree >= tofree_all + nitems(tofree_all)) {
 		/*
 		 * This won't happen as-is:
-		 * we've got 8 slots and allocate 4 things at most.
+		 * we've got 8 slots and allocate 5 things at most.
 		 */
 		fprintf(stderr,
 		    PROGNAME "[%d]: %s: need to free %zu > %zu!\n",