diff --git a/async/test/es6-generators.ts b/async/test/es6-generators.ts
index 721ae2e78c..f269902b60 100644
--- a/async/test/es6-generators.ts
+++ b/async/test/es6-generators.ts
@@ -3,7 +3,7 @@ function* funcCollection<T>(): IterableIterator<T> { }
 function funcMapIterator<T, E>(value: T, callback: AsyncResultCallback<T, E>) { }
 function funcMapComplete<T, E>(error: E, results: T[]) { }
 
-function funcCbErrBoolean<T>(v: T, cb: (err: Error, res: boolean) => void) { }
+function booleanIterator<T>(v: T, cb: (err: Error, res: boolean) => void) { }
 
 function eachIterator<T, E>(item: T, callback: (err: Error) => void) { }
 function eachOfIterator<T, K, E>(item: T, key: K, callback: (err: Error) => void) { }
@@ -14,16 +14,16 @@ async.map(funcCollection(), funcMapIterator, funcMapComplete)
 async.mapSeries(funcCollection(), funcMapIterator, funcMapComplete)
 async.mapLimit(funcCollection(), 2, funcMapIterator, funcMapComplete)
 
-async.filter(funcCollection(), funcCbErrBoolean, function (err: Error, results: any[]) { })
-async.filterSeries(funcCollection(), funcCbErrBoolean, function (err: Error, results: any[]) { })
-async.filterLimit(funcCollection(), 2, funcCbErrBoolean, function (err: Error, results: any[]) { })
-async.select(funcCollection(), funcCbErrBoolean, function (err: Error, results: any[]) { })
-async.selectSeries(funcCollection(), funcCbErrBoolean, function (err: Error, results: any[]) { })
-async.selectLimit(funcCollection(), 2, funcCbErrBoolean, function (err: Error, results: any[]) { })
+async.filter(funcCollection(), booleanIterator, function (err: Error, results: any[]) { })
+async.filterSeries(funcCollection(), booleanIterator, function (err: Error, results: any[]) { })
+async.filterLimit(funcCollection(), 2, booleanIterator, function (err: Error, results: any[]) { })
+async.select(funcCollection(), booleanIterator, function (err: Error, results: any[]) { })
+async.selectSeries(funcCollection(), booleanIterator, function (err: Error, results: any[]) { })
+async.selectLimit(funcCollection(), 2, booleanIterator, function (err: Error, results: any[]) { })
 
-async.reject(funcCollection(), funcCbErrBoolean, function (err: Error, results: any[]) { })
-async.rejectSeries(funcCollection(), funcCbErrBoolean, function (err: Error, results: any[]) { })
-async.rejectLimit(funcCollection(), 2, funcCbErrBoolean, function (err: Error, results: any[]) { })
+async.reject(funcCollection(), booleanIterator, function (err: Error, results: any[]) { })
+async.rejectSeries(funcCollection(), booleanIterator, function (err: Error, results: any[]) { })
+async.rejectLimit(funcCollection(), 2, booleanIterator, function (err: Error, results: any[]) { })
 
 async.each(funcCollection(), eachIterator, function (err: Error) { })
 async.eachLimit(funcCollection(), 2, eachIterator, function (err: Error) { })
@@ -38,17 +38,17 @@ async.forEachOf(funcCollection(), eachOfIterator, function (err: Error) { })
 async.forEachOfLimit(funcCollection(), 2, eachOfIterator, function (err: Error) { })
 async.forEachOfSeries(funcCollection(), eachOfIterator, function (err: Error) { })
 
-async.every(funcCollection(), funcCbErrBoolean, function (err: Error, res: boolean) { })
-async.everyLimit(funcCollection(), 2, funcCbErrBoolean, function (err: Error, res: boolean) { })
-async.everySeries(funcCollection(), funcCbErrBoolean, function (err: Error, res: boolean) { })
+async.every(funcCollection(), booleanIterator, function (err: Error, res: boolean) { })
+async.everyLimit(funcCollection(), 2, booleanIterator, function (err: Error, res: boolean) { })
+async.everySeries(funcCollection(), booleanIterator, function (err: Error, res: boolean) { })
 
-async.some(funcCollection(), funcCbErrBoolean, function (err: Error, res: boolean) { })
-async.someLimit(funcCollection(), 2, funcCbErrBoolean, function (err: Error, res: boolean) { })
-async.someSeries(funcCollection(), funcCbErrBoolean, function (err: Error, res: boolean) { })
+async.some(funcCollection(), booleanIterator, function (err: Error, res: boolean) { })
+async.someLimit(funcCollection(), 2, booleanIterator, function (err: Error, res: boolean) { })
+async.someSeries(funcCollection(), booleanIterator, function (err: Error, res: boolean) { })
 
-async.detect(funcCollection(), funcCbErrBoolean, function (err: Error, res: boolean) { })
-async.detectLimit(funcCollection(), 2, funcCbErrBoolean, function (err: Error, res: boolean) { })
-async.detectSeries(funcCollection(), funcCbErrBoolean, function (err: Error, res: boolean) { })
+async.detect(funcCollection(), booleanIterator, function (err: Error, res: boolean) { })
+async.detectLimit(funcCollection(), 2, booleanIterator, function (err: Error, res: boolean) { })
+async.detectSeries(funcCollection(), booleanIterator, function (err: Error, res: boolean) { })
 
 async.concat(funcCollection(), concatIterator, (err: Error, res) => { })
 async.concatSeries(funcCollection(), concatIterator, (err: Error, res) => { })