diff --git a/src/core/evaluator.js b/src/core/evaluator.js
index 547bee2fa..676f72a23 100644
--- a/src/core/evaluator.js
+++ b/src/core/evaluator.js
@@ -2960,7 +2960,10 @@ var EvaluatorPreprocessor = (function EvaluatorPreprocessorClosure() {
     this.opMap = getOPMap();
     // TODO(mduan): pass array of knownCommands rather than this.opMap
     // dictionary
-    this.parser = new Parser(new Lexer(stream, this.opMap), false, xref);
+    this.parser = new Parser({
+      lexer: new Lexer(stream, this.opMap),
+      xref,
+    });
     this.stateManager = stateManager;
     this.nonProcessedArgs = [];
     this._numInvalidPathOPS = 0;
diff --git a/src/core/obj.js b/src/core/obj.js
index ffb800534..1b47952dc 100644
--- a/src/core/obj.js
+++ b/src/core/obj.js
@@ -1477,8 +1477,12 @@ var XRef = (function XRefClosure() {
       let trailerDict;
       for (i = 0, ii = trailers.length; i < ii; ++i) {
         stream.pos = trailers[i];
-        var parser = new Parser(new Lexer(stream), /* allowStreams = */ true,
-                                /* xref = */ this, /* recoveryMode = */ true);
+        const parser = new Parser({
+          lexer: new Lexer(stream),
+          xref: this,
+          allowStreams: true,
+          recoveryMode: true,
+        });
         var obj = parser.getObj();
         if (!isCmd(obj, 'trailer')) {
           continue;
@@ -1536,7 +1540,11 @@ var XRef = (function XRefClosure() {
 
           stream.pos = startXRef + stream.start;
 
-          var parser = new Parser(new Lexer(stream), true, this);
+          const parser = new Parser({
+            lexer: new Lexer(stream),
+            xref: this,
+            allowStreams: true,
+          });
           var obj = parser.getObj();
           var dict;
 
@@ -1662,7 +1670,11 @@ var XRef = (function XRefClosure() {
       }
       var stream = this.stream.makeSubStream(xrefEntry.offset +
                                              this.stream.start);
-      var parser = new Parser(new Lexer(stream), true, this);
+      const parser = new Parser({
+        lexer: new Lexer(stream),
+        xref: this,
+        allowStreams: true,
+      });
       var obj1 = parser.getObj();
       var obj2 = parser.getObj();
       var obj3 = parser.getObj();
@@ -1709,8 +1721,11 @@ var XRef = (function XRefClosure() {
         throw new FormatError(
           'invalid first and n parameters for ObjStm stream');
       }
-      var parser = new Parser(new Lexer(stream), false, this);
-      parser.allowStreams = true;
+      const parser = new Parser({
+        lexer: new Lexer(stream),
+        xref: this,
+        allowStreams: true,
+      });
       var i, entries = [], num, nums = [];
       // read the object numbers to populate cache
       for (i = 0; i < n; ++i) {
diff --git a/src/core/parser.js b/src/core/parser.js
index e3fb9a836..723e2ea3e 100644
--- a/src/core/parser.js
+++ b/src/core/parser.js
@@ -51,10 +51,10 @@ function computeAdler32(bytes) {
 }
 
 class Parser {
-  constructor(lexer, allowStreams, xref, recoveryMode = false) {
+  constructor({ lexer, xref, allowStreams = false, recoveryMode = false, }) {
     this.lexer = lexer;
-    this.allowStreams = allowStreams;
     this.xref = xref;
+    this.allowStreams = allowStreams;
     this.recoveryMode = recoveryMode;
 
     this.imageCache = Object.create(null);
@@ -748,7 +748,7 @@ function toHexDigit(ch) {
 }
 
 class Lexer {
-  constructor(stream, knownCommands) {
+  constructor(stream, knownCommands = null) {
     this.stream = stream;
     this.nextChar();
 
@@ -1202,7 +1202,10 @@ class Linearization {
       throw new Error('Hint array in the linearization dictionary is invalid.');
     }
 
-    const parser = new Parser(new Lexer(stream), false, null);
+    const parser = new Parser({
+      lexer: new Lexer(stream),
+      xref: null,
+    });
     const obj1 = parser.getObj();
     const obj2 = parser.getObj();
     const obj3 = parser.getObj();
diff --git a/test/unit/annotation_spec.js b/test/unit/annotation_spec.js
index da2457404..8c17cf6fd 100644
--- a/test/unit/annotation_spec.js
+++ b/test/unit/annotation_spec.js
@@ -409,8 +409,10 @@ describe('annotation', function() {
         '/URI (http://www.example.com/\\303\\274\\303\\266\\303\\244)\n' +
         '>>\n'
       );
-      const lexer = new Lexer(actionStream);
-      const parser = new Parser(lexer);
+      const parser = new Parser({
+        lexer: new Lexer(actionStream),
+        xref: null,
+      });
       const actionDict = parser.getObj();
 
       const annotationDict = new Dict();
@@ -1412,8 +1414,11 @@ describe('annotation', function() {
         'Test attachment' +
         'endstream\n'
       );
-      const lexer = new Lexer(fileStream);
-      const parser = new Parser(lexer, /* allowStreams = */ true);
+      const parser = new Parser({
+        lexer: new Lexer(fileStream),
+        xref: null,
+        allowStreams: true,
+      });
 
       const fileStreamRef = Ref.get(18, 0);
       const fileStreamDict = parser.getObj();
diff --git a/test/unit/parser_spec.js b/test/unit/parser_spec.js
index 4e0404bba..721cb7b29 100644
--- a/test/unit/parser_spec.js
+++ b/test/unit/parser_spec.js
@@ -26,9 +26,12 @@ describe('parser', function() {
         const string = 'q 1 0 0 1 0 0 cm BI /W 10 /H 10 /BPC 1 ' +
                        '/F /A85 ID abc123~> EI Q';
         const input = new StringStream(string);
-        const lexer = new Lexer(input);
-        const parser = new Parser(lexer, /* allowStreams = */ true,
-                                  /* xref = */ null);
+        const parser = new Parser({
+          lexer: new Lexer(input),
+          xref: null,
+          allowStreams: true,
+        });
+
         parser.inlineStreamSkipEI(input);
         expect(input.pos).toEqual(string.indexOf('Q'));
         expect(input.peekByte()).toEqual(0x51); // 'Q'
@@ -39,9 +42,12 @@ describe('parser', function() {
         const string = 'q 1 0 0 1 0 0 cm BI /W 10 /H 10 /BPC 1 ' +
                        '/F /A85 ID abc123~> Q';
         const input = new StringStream(string);
-        const lexer = new Lexer(input);
-        const parser = new Parser(lexer, /* allowStreams = */ true,
-                                  /* xref = */ null);
+        const parser = new Parser({
+          lexer: new Lexer(input),
+          xref: null,
+          allowStreams: true,
+        });
+
         parser.inlineStreamSkipEI(input);
         expect(input.pos).toEqual(string.length);
         expect(input.peekByte()).toEqual(-1);