Index: head/sbin/geom/class/eli/geom_eli.c
===================================================================
--- head/sbin/geom/class/eli/geom_eli.c
+++ head/sbin/geom/class/eli/geom_eli.c
@@ -1118,7 +1118,9 @@
 
 	val = gctl_get_intmax(req, "iterations");
 	/* Check if iterations number should and can be changed. */
-	if (val != -1) {
+	if (val != -1 && md->md_iterations == -1) {
+		md->md_iterations = val;
+	} else if (val != -1 && val != md->md_iterations) {
 		if (bitcount32(md->md_keys) != 1) {
 			gctl_error(req, "To be able to use '-i' option, only "
 			    "one key can be defined.");
Index: head/sys/geom/eli/g_eli_ctl.c
===================================================================
--- head/sys/geom/eli/g_eli_ctl.c
+++ head/sys/geom/eli/g_eli_ctl.c
@@ -618,7 +618,9 @@
 		return;
 	}
 	/* Check if iterations number should and can be changed. */
-	if (*valp != -1) {
+	if (*valp != -1 && md.md_iterations == -1) {
+		md.md_iterations = *valp;
+	} else if (*valp != -1 && *valp != md.md_iterations) {
 		if (bitcount32(md.md_keys) != 1) {
 			gctl_error(req, "To be able to use '-i' option, only "
 			    "one key can be defined.");