diff --git a/src/lex.js b/src/lex.js
index c5431649a1..9a078ea79a 100644
--- a/src/lex.js
+++ b/src/lex.js
@@ -966,11 +966,19 @@ Lexer.prototype = {
       }
     }
 
+    // TODO: Extend this check to other numeric literals
+    this.triggerAsync("warning", {
+      code: "W045",
+      line: this.line,
+      character: this.char + value.length,
+      data: [ value ]
+    }, checks, function() { return !isFinite(value); });
+
     return {
       type: Token.NumericLiteral,
       value: value,
       base: base,
-      isMalformed: !isFinite(value)
+      isMalformed: false
     };
   },
 
@@ -2143,10 +2151,8 @@ Lexer.prototype = {
 
       case Token.NumericLiteral:
         if (token.isMalformed) {
-          // This condition unequivocally describes a syntax error.
-          // TODO: Re-factor as an "error" (not a "warning").
-          this.trigger("warning", {
-            code: "W045",
+          this.trigger("error", {
+            code: "E067",
             line: this.line,
             character: this.char,
             data: [ token.value ]
diff --git a/src/messages.js b/src/messages.js
index cce95ff773..e541cdeb19 100644
--- a/src/messages.js
+++ b/src/messages.js
@@ -82,7 +82,8 @@ var errors = {
   E064: "Super call may only be used within class method bodies.",
   E065: "Functions defined outside of strict mode with non-simple parameter lists may not " +
     "enable strict mode.",
-  E066: "Asynchronous iteration is only available with for-of loops."
+  E066: "Asynchronous iteration is only available with for-of loops.",
+  E067: "Malformed numeric literal: '{a}'."
 };
 
 var warnings = {
@@ -131,7 +132,8 @@ var warnings = {
   W042: "Avoid EOL escaping.",
   W043: "Bad escaping of EOL. Use option multistr if needed.",
   W044: "Bad or unnecessary escaping.", /* TODO(caitp): remove W044 */
-  W045: "Bad number '{a}'.",
+  W045: "Value described by numeric literal cannot be accurately " +
+    "represented with a number value: '{a}'.",
   W046: "Don't use extra leading zeros '{a}'.",
   W047: "A trailing decimal point can be confused with a dot: '{a}'.",
   W048: "Unexpected control character in regular expression.",
diff --git a/tests/test262/expectations.txt b/tests/test262/expectations.txt
index d90d2ea097..c8836ca755 100644
--- a/tests/test262/expectations.txt
+++ b/tests/test262/expectations.txt
@@ -150,15 +150,7 @@ test/language/rest-parameters/object-pattern.js(strict mode)
 test/language/arguments-object/10.6-13-c-1-s.js(strict mode)
 test/language/arguments-object/10.6-1gs.js(strict mode)
 test/language/arguments-object/10.6-2gs.js(strict mode)
-test/language/literals/numeric/S7.8.3_A6.1_T1.js(default)
-test/language/literals/numeric/S7.8.3_A6.1_T1.js(strict mode)
-test/language/literals/numeric/S7.8.3_A6.1_T2.js(default)
-test/language/literals/numeric/S7.8.3_A6.1_T2.js(strict mode)
-test/language/literals/numeric/binary-invalid-truncated.js(default)
-test/language/literals/numeric/binary-invalid-truncated.js(strict mode)
 test/language/literals/numeric/non-octal-decimal-integer-strict.js(strict mode)
-test/language/literals/numeric/octal-invalid-truncated.js(default)
-test/language/literals/numeric/octal-invalid-truncated.js(strict mode)
 test/language/block-scope/syntax/function-declarations/in-statement-position-if-expression-statement-else-statement.js(strict mode)
 test/language/block-scope/syntax/function-declarations/in-statement-position-if-expression-statement.js(strict mode)
 test/language/destructuring/binding/syntax/array-elements-with-initializer.js(default)
diff --git a/tests/unit/parser.js b/tests/unit/parser.js
index 034a186c6c..c1c8159237 100644
--- a/tests/unit/parser.js
+++ b/tests/unit/parser.js
@@ -537,7 +537,7 @@ exports.numbers = function (test) {
   ];
 
   TestRun(test)
-    .addError(2, 15, "Bad number '10e308'.")
+    .addError(2, 15, "Value described by numeric literal cannot be accurately represented with a number value: '10e308'.")
     .addError(5, 11, "A leading decimal point can be confused with a dot: '.3'.")
     .addError(6, 9, "Unexpected '0'.")
     .addError(7, 1, "Expected an identifier and instead saw 'var'.")
@@ -547,7 +547,7 @@ exports.numbers = function (test) {
     .addError(9, 9, "A dot following a number can be confused with a decimal point.")
     .addError(11, 9, "'Octal integer literal' is only available in ES6 (use 'esversion: 6').")
     .addError(12, 9, "'Binary integer literal' is only available in ES6 (use 'esversion: 6').")
-    .addError(13, 11, "Bad number '0x'.")
+    .addError(13, 11, "Malformed numeric literal: '0x'.")
     .addError(15, 9, "Unexpected '1'.")
     .addError(16, 11, "Expected an identifier and instead saw ';'.")
     .addError(16, 1, "Expected an identifier and instead saw 'var'.")
diff --git a/tests/unit/unstable/bigint.js b/tests/unit/unstable/bigint.js
index 174505bc96..a299cca847 100644
--- a/tests/unit/unstable/bigint.js
+++ b/tests/unit/unstable/bigint.js
@@ -75,19 +75,19 @@ exports.invalid = function (test) {
     .test("void 1e3n;", {esversion: 6, unstable: {bigint: true}});
 
   TestRun(test, "invalid hex digit")
-    .addError(1, 8, "Bad number '0x'.")
+    .addError(1, 8, "Malformed numeric literal: '0x'.")
     .addError(1, 8, "Missing semicolon.")
     .addError(1, 8, "Expected an assignment or function call and instead saw an expression.")
     .test("void 0xgn;", {esversion: 6, unstable: {bigint: true}});
 
   TestRun(test, "invalid binary digit")
-    .addError(1, 8, "Bad number '0b'.")
+    .addError(1, 8, "Malformed numeric literal: '0b'.")
     .addError(1, 8, "Missing semicolon.")
     .addError(1, 8, "Expected an assignment or function call and instead saw an expression.")
     .test("void 0b2n;", {esversion: 6, unstable: {bigint: true}});
 
   TestRun(test, "invalid octal digit")
-    .addError(1, 8, "Bad number '0o'.")
+    .addError(1, 8, "Malformed numeric literal: '0o'.")
     .addError(1, 8, "Missing semicolon.")
     .addError(1, 8, "Expected an assignment or function call and instead saw an expression.")
     .test("void 0o8n;", {esversion: 6, unstable: {bigint: true}});