diff --git a/src/mol-base/collections/integer/impl/segmentation.ts b/src/mol-base/collections/integer/impl/segmentation.ts
index f9b7d6f4230aca4c34c4f8f638620677d648a8ef..567eee22ded8433c20cdb7d18d8ad3ca0205924b 100644
--- a/src/mol-base/collections/integer/impl/segmentation.ts
+++ b/src/mol-base/collections/integer/impl/segmentation.ts
@@ -72,7 +72,7 @@ export class SegmentIterator implements Iterator<Segs.Segment> {
 
     private updateValue() {
         const segmentEnd = this.segments[this.segmentMin + 1];
-        const setEnd = OrderedSet.findPredecessorIndexInRange(this.set, segmentEnd, this.setRange);
+        const setEnd = OrderedSet.findPredecessorIndexInInterval(this.set, segmentEnd, this.setRange);
         this.value.start = Interval.start(this.setRange);
         this.value.end = setEnd;
         const rEnd = Interval.end(this.setRange);
diff --git a/src/mol-base/collections/integer/ordered-set.ts b/src/mol-base/collections/integer/ordered-set.ts
index ab7af67becfb4362f6890e0bff077d640d4859e1..b0291432db0b1d9db5afed281ea253c2d600d633 100644
--- a/src/mol-base/collections/integer/ordered-set.ts
+++ b/src/mol-base/collections/integer/ordered-set.ts
@@ -33,7 +33,7 @@ namespace OrderedSet {
     export const subtract: (a: OrderedSet, b: OrderedSet) => OrderedSet = Base.subtract as any;
 
     export const findPredecessorIndex: (set: OrderedSet, x: number) => number = Base.findPredecessorIndex as any;
-    export const findPredecessorIndexInRange: (set: OrderedSet, x: number, range: Interval) => number = Base.findPredecessorIndexInInterval as any;
+    export const findPredecessorIndexInInterval: (set: OrderedSet, x: number, range: Interval) => number = Base.findPredecessorIndexInInterval as any;
     export const findRange: (set: OrderedSet, min: number, max: number) => Interval = Base.findRange as any;
 }
 
diff --git a/src/perf-tests/structure.ts b/src/perf-tests/structure.ts
index 34d5126ac3b557a8b408f68a60910c33bc92e657..2ed618f6517f3923b30ec2bda5a339a0ec66c29c 100644
--- a/src/perf-tests/structure.ts
+++ b/src/perf-tests/structure.ts
@@ -262,7 +262,12 @@ export namespace PropertyAccess {
         const q1 = Q.generators.atomGroups({ residueTest: l => auth_comp_id(l) === 'ALA' });
         //const q2 = Q.generators.atomGroups({ chainTest: l => set.has(auth_asym_id(l)),  residueTest: l => auth_comp_id(l) === 'ALA' });
         q(structures[0]);
+        console.time('q1')
         q1(structures[0]);
+        console.timeEnd('q1')
+        console.time('q1')
+        q1(structures[0]);
+        console.timeEnd('q1')
         //console.log(q1(structures[0]));
 
         //const col = models[0].conformation.atomId.value;