diff --git a/iter-list.go b/iter-list.go
index ed5a554..f7b44a4 100644
--- a/iter-list.go
+++ b/iter-list.go
@@ -26,21 +26,21 @@ func NewListIterator(list *ListType, args []any) (it *ListIterator) {
 	}
 	it = &ListIterator{a: list, count: 0, index: -1, start: 0, stop: listLen - 1, step: 1}
 	if argc >= 1 {
-		if i, err := ToInt(args[0], "start index"); err == nil {
+		if i, err := ToGoInt(args[0], "start index"); err == nil {
 			if i < 0 {
 				i = listLen + i
 			}
 			it.start = i
 		}
 		if argc >= 2 {
-			if i, err := ToInt(args[1], "stop index"); err == nil {
+			if i, err := ToGoInt(args[1], "stop index"); err == nil {
 				if i < 0 {
 					i = listLen + i
 				}
 				it.stop = i
 			}
 			if argc >= 3 {
-				if i, err := ToInt(args[2], "step"); err == nil {
+				if i, err := ToGoInt(args[2], "step"); err == nil {
 					if i < 0 {
 						i = -i
 					}
diff --git a/operator-index.go b/operator-index.go
index af91069..0df3292 100644
--- a/operator-index.go
+++ b/operator-index.go
@@ -23,7 +23,7 @@ func verifyKey(indexTerm *term, indexList *ListType) (index any, err error) {
 func verifyIndex(indexTerm *term, indexList *ListType, maxValue int) (index int, err error) {
 	var v int
 
-	if v, err = ToInt((*indexList)[0], "index expression"); err == nil {
+	if v, err = ToGoInt((*indexList)[0], "index expression"); err == nil {
 		if v < 0 && v >= -maxValue {
 			v = maxValue + v
 		}
diff --git a/operator-length.go b/operator-length.go
index e2b53c1..80c9ee6 100644
--- a/operator-length.go
+++ b/operator-length.go
@@ -36,7 +36,7 @@ func evalLength(ctx ExprContext, self *term) (v any, err error) {
 	} else if it, ok := childValue.(Iterator); ok {
 		if extIt, ok := childValue.(ExtIterator); ok && extIt.HasOperation(countName) {
 			count, _ := extIt.CallOperation(countName, nil)
-			v, _ = ToInt(count, "")
+			v, _ = ToGoInt(count, "")
 		} else {
 			v = int64(it.Index() + 1)
 		}