diff --git a/package.json b/package.json
index 0dcda114..accf4adc 100644
--- a/package.json
+++ b/package.json
@@ -47,8 +47,7 @@
   },
   "dependencies": {
     "debug": "^3.1.0",
-    "es6-promise": "^4.2.4",
-    "then-read-stream": "^1.2.1",
+    "then-read-stream": "^1.3.0",
     "token-types": "^0.10.0"
   },
   "keywords": [
diff --git a/src/AbstractTokenizer.ts b/src/AbstractTokenizer.ts
index ec3d18ac..efb7d895 100644
--- a/src/AbstractTokenizer.ts
+++ b/src/AbstractTokenizer.ts
@@ -1,6 +1,5 @@
 import {IGetToken, IToken} from "token-types";
 import {endOfFile, ITokenizer} from "./";
-import {Promise} from "es6-promise";
 
 export abstract class AbstractTokenizer implements ITokenizer {
 
diff --git a/src/BufferTokenizer.ts b/src/BufferTokenizer.ts
index a7861c38..fd857b3a 100644
--- a/src/BufferTokenizer.ts
+++ b/src/BufferTokenizer.ts
@@ -1,5 +1,4 @@
 import {endOfFile} from "./";
-import {Promise} from "es6-promise";
 import {ITokenizer} from "./index";
 import {IGetToken, IToken} from "token-types";
 
diff --git a/src/FileTokenizer.ts b/src/FileTokenizer.ts
index a0ee963f..a4094977 100644
--- a/src/FileTokenizer.ts
+++ b/src/FileTokenizer.ts
@@ -1,6 +1,5 @@
 import {AbstractTokenizer} from "./AbstractTokenizer";
 import {endOfFile} from "./";
-import {Promise} from "es6-promise";
 import {FsPromise} from "./FsPromise";
 
 export class FileTokenizer extends AbstractTokenizer {
diff --git a/src/FsPromise.ts b/src/FsPromise.ts
index 4ac6f879..f2d971cf 100644
--- a/src/FsPromise.ts
+++ b/src/FsPromise.ts
@@ -1,5 +1,4 @@
 import * as fs from "fs";
-import {Promise} from "es6-promise";
 
 export interface IReadResult {
   bytesRead: number,
diff --git a/src/ReadStreamTokenizer.ts b/src/ReadStreamTokenizer.ts
index 0203898b..c325c7fd 100644
--- a/src/ReadStreamTokenizer.ts
+++ b/src/ReadStreamTokenizer.ts
@@ -2,7 +2,6 @@ import {AbstractTokenizer} from "./AbstractTokenizer";
 import {endOfFile} from "./";
 import {endOfStream, StreamReader} from "then-read-stream";
 import * as Stream from "stream";
-import {Promise} from "es6-promise";
 
 import * as _debug from "debug";
 const debug = _debug("strtok3:ReadStreamTokenizer");
diff --git a/src/index.ts b/src/index.ts
index fbf78add..1881dbc4 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -2,7 +2,6 @@ import {IGetToken} from 'token-types';
 import {ReadStreamTokenizer} from "./ReadStreamTokenizer";
 import {FileTokenizer} from "./FileTokenizer";
 import * as Stream from "stream";
-import {Promise} from "es6-promise";
 import {FsPromise} from "./FsPromise";
 import {BufferTokenizer} from "./BufferTokenizer";
 
diff --git a/src/tsconfig.json b/src/tsconfig.json
index 47631a83..a2756074 100644
--- a/src/tsconfig.json
+++ b/src/tsconfig.json
@@ -1,11 +1,11 @@
 {
   "compilerOptions": {
-    "sourceMap": true,
+    "sourceMap": false,
     "inlineSources": false,
     "module": "commonjs",
     "moduleResolution": "node",
     "declaration": true,
-    "target": "es5",
+    "target": "es6",
     "outDir": "../lib"
   }
 }
diff --git a/test/tsconfig.json b/test/tsconfig.json
index 8c871630..5f281b26 100644
--- a/test/tsconfig.json
+++ b/test/tsconfig.json
@@ -5,7 +5,7 @@
     "module": "commonjs",
     "moduleResolution": "node",
     "declaration": false,
-    "target": "es5"
+    "target": "es6"
   }
 }
 
diff --git a/yarn.lock b/yarn.lock
index 7b0a4cae..1da82aaf 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -535,10 +535,6 @@ error-ex@^1.2.0, error-ex@^1.3.1:
   dependencies:
     is-arrayish "^0.2.1"
 
-es6-promise@^4.2.4:
-  version "4.2.4"
-  resolved "https://registry.yarnpkg.com/es6-promise/-/es6-promise-4.2.4.tgz#dc4221c2b16518760bd8c39a52d8f356fc00ed29"
-
 escape-string-regexp@1.0.5, escape-string-regexp@^1.0.2, escape-string-regexp@^1.0.5:
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/escape-string-regexp/-/escape-string-regexp-1.0.5.tgz#1b61c0562190a8dff6ae3bb2cf0200ca130b86d4"
@@ -1725,11 +1721,9 @@ test-exclude@^4.2.2:
     read-pkg-up "^3.0.0"
     require-main-filename "^1.0.1"
 
-then-read-stream@^1.2.1:
-  version "1.2.1"
-  resolved "https://registry.yarnpkg.com/then-read-stream/-/then-read-stream-1.2.1.tgz#9baddcb8a4ebc8a6fb36436985d24c36f7908829"
-  dependencies:
-    es6-promise "^4.2.4"
+then-read-stream@^1.3.0:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/then-read-stream/-/then-read-stream-1.3.0.tgz#fb99314d1c5845fea29e5d271f261a1259039c09"
 
 timed-out@^4.0.0:
   version "4.0.1"