diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index ab8e52e3dfa..a072579ed63 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -1429,9 +1429,13 @@ namespace ts {
                     return token() === SyntaxKind.CommaToken || token() === SyntaxKind.DotDotDotToken || isIdentifierOrPattern();
                 case ParsingContext.TypeParameters:
                     return isIdentifier();
-                case ParsingContext.ArgumentExpressions:
                 case ParsingContext.ArrayLiteralMembers:
-                    return token() === SyntaxKind.CommaToken || token() === SyntaxKind.DotDotDotToken || isStartOfExpression();
+                    if (token() === SyntaxKind.CommaToken) {
+                        return true;
+                    }
+                    // falls through
+                case ParsingContext.ArgumentExpressions:
+                    return token() === SyntaxKind.DotDotDotToken || isStartOfExpression();
                 case ParsingContext.Parameters:
                     return isStartOfParameter();
                 case ParsingContext.TypeArguments:
diff --git a/tests/baselines/reference/importCallExpressionGrammarError.errors.txt b/tests/baselines/reference/importCallExpressionGrammarError.errors.txt
index 6d64808e111..b39228f100d 100644
--- a/tests/baselines/reference/importCallExpressionGrammarError.errors.txt
+++ b/tests/baselines/reference/importCallExpressionGrammarError.errors.txt
@@ -1,13 +1,11 @@
 tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts(5,8): error TS1325: Specifier of dynamic import cannot be spread element.
 tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts(7,17): error TS1325: Specifier of dynamic import cannot be spread element.
 tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts(8,12): error TS1324: Dynamic import must have one specifier as an argument.
-tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts(9,19): error TS1135: Argument expression expected.
-tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts(9,19): error TS7036: Dynamic import's specifier must be of type 'string', but here has type 'undefined'.
-tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts(10,12): error TS1324: Dynamic import must have one specifier as an argument.
-tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts(10,19): error TS2307: Cannot find module 'pathToModule'.
+tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts(9,12): error TS1324: Dynamic import must have one specifier as an argument.
+tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts(9,19): error TS2307: Cannot find module 'pathToModule'.
 
 
-==== tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts (7 errors) ====
+==== tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts (5 errors) ====
     declare function getSpecifier(): string;
     declare var whatToLoad: boolean;
     
@@ -22,11 +20,6 @@ tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts(10,19)
     const p2 = import();
                ~~~~~~~~
 !!! error TS1324: Dynamic import must have one specifier as an argument.
-    const p3 = import(,);
-                      
-!!! error TS1135: Argument expression expected.
-                      
-!!! error TS7036: Dynamic import's specifier must be of type 'string', but here has type 'undefined'.
     const p4 = import("pathToModule", "secondModule");
                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 !!! error TS1324: Dynamic import must have one specifier as an argument.
diff --git a/tests/baselines/reference/importCallExpressionGrammarError.js b/tests/baselines/reference/importCallExpressionGrammarError.js
index 435eab35d4e..61b47759581 100644
--- a/tests/baselines/reference/importCallExpressionGrammarError.js
+++ b/tests/baselines/reference/importCallExpressionGrammarError.js
@@ -7,7 +7,6 @@ import(...["PathModule"]);
 
 var p1 = import(...a);
 const p2 = import();
-const p3 = import(,);
 const p4 = import("pathToModule", "secondModule");
 
 //// [importCallExpressionGrammarError.js]
@@ -15,5 +14,4 @@ var a = ["./0"];
 Promise.resolve().then(() => require(...["PathModule"]));
 var p1 = Promise.resolve().then(() => require(...a));
 const p2 = Promise.resolve().then(() => require());
-const p3 = Promise.resolve().then(() => require());
 const p4 = Promise.resolve().then(() => require("pathToModule"));
diff --git a/tests/baselines/reference/importCallExpressionGrammarError.symbols b/tests/baselines/reference/importCallExpressionGrammarError.symbols
index 7fce3af41b5..b4a0efd052e 100644
--- a/tests/baselines/reference/importCallExpressionGrammarError.symbols
+++ b/tests/baselines/reference/importCallExpressionGrammarError.symbols
@@ -17,9 +17,6 @@ var p1 = import(...a);
 const p2 = import();
 >p2 : Symbol(p2, Decl(importCallExpressionGrammarError.ts, 7, 5))
 
-const p3 = import(,);
->p3 : Symbol(p3, Decl(importCallExpressionGrammarError.ts, 8, 5))
-
 const p4 = import("pathToModule", "secondModule");
->p4 : Symbol(p4, Decl(importCallExpressionGrammarError.ts, 9, 5))
+>p4 : Symbol(p4, Decl(importCallExpressionGrammarError.ts, 8, 5))
 
diff --git a/tests/baselines/reference/importCallExpressionGrammarError.types b/tests/baselines/reference/importCallExpressionGrammarError.types
index c9f95fbcb6b..2e2a8221a07 100644
--- a/tests/baselines/reference/importCallExpressionGrammarError.types
+++ b/tests/baselines/reference/importCallExpressionGrammarError.types
@@ -26,11 +26,6 @@ const p2 = import();
 >p2 : Promise<any>
 >import() : Promise<any>
 
-const p3 = import(,);
->p3 : Promise<any>
->import(,) : Promise<any>
-> : undefined
-
 const p4 = import("pathToModule", "secondModule");
 >p4 : Promise<any>
 >import("pathToModule", "secondModule") : Promise<any>
diff --git a/tests/baselines/reference/missingArgument1.errors.txt b/tests/baselines/reference/missingArgument1.errors.txt
index ba2bb0892f2..7530da802c8 100644
--- a/tests/baselines/reference/missingArgument1.errors.txt
+++ b/tests/baselines/reference/missingArgument1.errors.txt
@@ -10,7 +10,7 @@ tests/cases/compiler/missingArgument1.ts(1,8): error TS2304: Cannot find name 'b
 !!! error TS2304: Cannot find name 'foo'.
         ~
 !!! error TS2304: Cannot find name 'a'.
-          
+          ~
 !!! error TS1135: Argument expression expected.
            ~
 !!! error TS2304: Cannot find name 'b'.
\ No newline at end of file
diff --git a/tests/baselines/reference/missingArgument1.js b/tests/baselines/reference/missingArgument1.js
index eed0d9b11d6..94f78377e40 100644
--- a/tests/baselines/reference/missingArgument1.js
+++ b/tests/baselines/reference/missingArgument1.js
@@ -2,4 +2,4 @@
 foo(a,,b);
 
 //// [missingArgument1.js]
-foo(a, , b);
+foo(a, b);
diff --git a/tests/baselines/reference/missingArgument1.types b/tests/baselines/reference/missingArgument1.types
index 4b362a76145..b4468f4b3f6 100644
--- a/tests/baselines/reference/missingArgument1.types
+++ b/tests/baselines/reference/missingArgument1.types
@@ -3,6 +3,5 @@ foo(a,,b);
 >foo(a,,b) : any
 >foo : any
 >a : any
-> : undefined
 >b : any
 
diff --git a/tests/baselines/reference/parseErrorDoubleCommaInCall.errors.txt b/tests/baselines/reference/parseErrorDoubleCommaInCall.errors.txt
new file mode 100644
index 00000000000..f209456d81f
--- /dev/null
+++ b/tests/baselines/reference/parseErrorDoubleCommaInCall.errors.txt
@@ -0,0 +1,10 @@
+tests/cases/compiler/parseErrorDoubleCommaInCall.ts(2,10): error TS1136: Property assignment expected.
+
+
+==== tests/cases/compiler/parseErrorDoubleCommaInCall.ts (1 errors) ====
+    Boolean({
+        x: 0,,
+             ~
+!!! error TS1136: Property assignment expected.
+    });
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/parseErrorDoubleCommaInCall.js b/tests/baselines/reference/parseErrorDoubleCommaInCall.js
new file mode 100644
index 00000000000..f1a50cccfde
--- /dev/null
+++ b/tests/baselines/reference/parseErrorDoubleCommaInCall.js
@@ -0,0 +1,10 @@
+//// [parseErrorDoubleCommaInCall.ts]
+Boolean({
+    x: 0,,
+});
+
+
+//// [parseErrorDoubleCommaInCall.js]
+Boolean({
+    x: 0
+});
diff --git a/tests/baselines/reference/parseErrorDoubleCommaInCall.symbols b/tests/baselines/reference/parseErrorDoubleCommaInCall.symbols
new file mode 100644
index 00000000000..fed8484d591
--- /dev/null
+++ b/tests/baselines/reference/parseErrorDoubleCommaInCall.symbols
@@ -0,0 +1,9 @@
+=== tests/cases/compiler/parseErrorDoubleCommaInCall.ts ===
+Boolean({
+>Boolean : Symbol(Boolean, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+
+    x: 0,,
+>x : Symbol(x, Decl(parseErrorDoubleCommaInCall.ts, 0, 9))
+
+});
+
diff --git a/tests/baselines/reference/parseErrorDoubleCommaInCall.types b/tests/baselines/reference/parseErrorDoubleCommaInCall.types
new file mode 100644
index 00000000000..23197748490
--- /dev/null
+++ b/tests/baselines/reference/parseErrorDoubleCommaInCall.types
@@ -0,0 +1,12 @@
+=== tests/cases/compiler/parseErrorDoubleCommaInCall.ts ===
+Boolean({
+>Boolean({    x: 0,,}) : boolean
+>Boolean : BooleanConstructor
+>{    x: 0,,} : { x: number; }
+
+    x: 0,,
+>x : number
+>0 : 0
+
+});
+
diff --git a/tests/baselines/reference/parserErrorRecovery_ArgumentList6.errors.txt b/tests/baselines/reference/parserErrorRecovery_ArgumentList6.errors.txt
index 7562fee7936..215c8da0f4f 100644
--- a/tests/baselines/reference/parserErrorRecovery_ArgumentList6.errors.txt
+++ b/tests/baselines/reference/parserErrorRecovery_ArgumentList6.errors.txt
@@ -1,10 +1,13 @@
 tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArgumentLists/parserErrorRecovery_ArgumentList6.ts(1,1): error TS2304: Cannot find name 'Foo'.
+tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArgumentLists/parserErrorRecovery_ArgumentList6.ts(1,5): error TS1135: Argument expression expected.
 tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArgumentLists/parserErrorRecovery_ArgumentList6.ts(1,6): error TS1005: ')' expected.
 
 
-==== tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArgumentLists/parserErrorRecovery_ArgumentList6.ts (2 errors) ====
+==== tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArgumentLists/parserErrorRecovery_ArgumentList6.ts (3 errors) ====
     Foo(,
     ~~~
 !!! error TS2304: Cannot find name 'Foo'.
+        ~
+!!! error TS1135: Argument expression expected.
          
 !!! error TS1005: ')' expected.
\ No newline at end of file
diff --git a/tests/baselines/reference/parserErrorRecovery_ArgumentList6.types b/tests/baselines/reference/parserErrorRecovery_ArgumentList6.types
index 202483685d7..8dee378e0a9 100644
--- a/tests/baselines/reference/parserErrorRecovery_ArgumentList6.types
+++ b/tests/baselines/reference/parserErrorRecovery_ArgumentList6.types
@@ -2,5 +2,4 @@
 Foo(,
 >Foo(, : any
 >Foo : any
-> : undefined
 
diff --git a/tests/baselines/reference/parserErrorRecovery_ArgumentList7.errors.txt b/tests/baselines/reference/parserErrorRecovery_ArgumentList7.errors.txt
index 3f4afaf930b..abe77ca9f1c 100644
--- a/tests/baselines/reference/parserErrorRecovery_ArgumentList7.errors.txt
+++ b/tests/baselines/reference/parserErrorRecovery_ArgumentList7.errors.txt
@@ -1,13 +1,16 @@
 tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArgumentLists/parserErrorRecovery_ArgumentList7.ts(1,1): error TS2304: Cannot find name 'Foo'.
 tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArgumentLists/parserErrorRecovery_ArgumentList7.ts(1,5): error TS2304: Cannot find name 'a'.
+tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArgumentLists/parserErrorRecovery_ArgumentList7.ts(1,7): error TS1135: Argument expression expected.
 tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArgumentLists/parserErrorRecovery_ArgumentList7.ts(1,8): error TS1005: ')' expected.
 
 
-==== tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArgumentLists/parserErrorRecovery_ArgumentList7.ts (3 errors) ====
+==== tests/cases/conformance/parser/ecmascript5/ErrorRecovery/ArgumentLists/parserErrorRecovery_ArgumentList7.ts (4 errors) ====
     Foo(a,,
     ~~~
 !!! error TS2304: Cannot find name 'Foo'.
         ~
 !!! error TS2304: Cannot find name 'a'.
+          ~
+!!! error TS1135: Argument expression expected.
            
 !!! error TS1005: ')' expected.
\ No newline at end of file
diff --git a/tests/baselines/reference/parserErrorRecovery_ArgumentList7.js b/tests/baselines/reference/parserErrorRecovery_ArgumentList7.js
index 94eba9445e9..dfe0f58332f 100644
--- a/tests/baselines/reference/parserErrorRecovery_ArgumentList7.js
+++ b/tests/baselines/reference/parserErrorRecovery_ArgumentList7.js
@@ -2,4 +2,4 @@
 Foo(a,,
 
 //// [parserErrorRecovery_ArgumentList7.js]
-Foo(a, );
+Foo(a);
diff --git a/tests/baselines/reference/parserErrorRecovery_ArgumentList7.types b/tests/baselines/reference/parserErrorRecovery_ArgumentList7.types
index 9de43329a13..ca95e4563e1 100644
--- a/tests/baselines/reference/parserErrorRecovery_ArgumentList7.types
+++ b/tests/baselines/reference/parserErrorRecovery_ArgumentList7.types
@@ -3,5 +3,4 @@ Foo(a,,
 >Foo(a,, : any
 >Foo : any
 >a : any
-> : undefined
 
diff --git a/tests/cases/compiler/parseErrorDoubleCommaInCall.ts b/tests/cases/compiler/parseErrorDoubleCommaInCall.ts
new file mode 100644
index 00000000000..2171e9262a9
--- /dev/null
+++ b/tests/cases/compiler/parseErrorDoubleCommaInCall.ts
@@ -0,0 +1,3 @@
+Boolean({
+    x: 0,,
+});
diff --git a/tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts b/tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts
index 38dc47f3207..609a70a2013 100644
--- a/tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts
+++ b/tests/cases/conformance/dynamicImport/importCallExpressionGrammarError.ts
@@ -10,5 +10,4 @@ import(...["PathModule"]);
 
 var p1 = import(...a);
 const p2 = import();
-const p3 = import(,);
 const p4 = import("pathToModule", "secondModule");
\ No newline at end of file
diff --git a/tests/cases/fourslash/signatureHelpOnOverloadsDifferentArity3.ts b/tests/cases/fourslash/signatureHelpOnOverloadsDifferentArity3.ts
index b98cfe6bbfe..d445997338b 100644
--- a/tests/cases/fourslash/signatureHelpOnOverloadsDifferentArity3.ts
+++ b/tests/cases/fourslash/signatureHelpOnOverloadsDifferentArity3.ts
@@ -13,14 +13,14 @@ verify.currentSignatureHelpIs("f(): any");
 verify.currentSignatureParameterCountIs(0);
 verify.signatureHelpArgumentCountIs(0);
 
-edit.insert(", ");
+edit.insert("x, ");
 verify.signatureHelpCountIs(4);
 verify.currentSignatureHelpIs("f(s: string, b: boolean): any");
 verify.currentSignatureParameterCountIs(2);
 verify.currentParameterHelpArgumentNameIs("b");
 verify.currentParameterSpanIs("b: boolean");
 
-edit.insert(", ");
+edit.insert("x, ");
 verify.signatureHelpCountIs(4);
 verify.currentSignatureHelpIs("f(s: string, b: boolean): any");
 verify.currentSignatureParameterCountIs(2);
\ No newline at end of file