diff --git a/src/mol-base/collections/database/column.ts b/src/mol-base/collections/database/column.ts
index 9f0263306e0f5fe5c10866c27cb7729856a0e995..f36ec2f9766ea2496eaed83aed939730febf28cb 100644
--- a/src/mol-base/collections/database/column.ts
+++ b/src/mol-base/collections/database/column.ts
@@ -14,7 +14,7 @@ interface Column<T> {
     readonly rowCount: number,
     value(row: number): T,
     valueKind(row: number): Column.ValueKind,
-    toArray(params?: Column.ToArrayParams<T>): ReadonlyArray<T>,
+    toArray(params?: Column.ToArrayParams<T>): ArrayLike<T>,
     areValuesEqual(rowA: number, rowB: number): boolean
 }