diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index b07c21fa4cb..835a8be3167 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -1,4 +1,4 @@
-/// <reference path="types.ts"/>
+/// <reference path="types.ts"/>
 /// <reference path="performance.ts" />
 
 
@@ -115,15 +115,6 @@ namespace ts {
         return -1;
     }
 
-    export function firstOrUndefined<T>(array: T[], predicate: (x: T) => boolean): T {
-        for (let i = 0, len = array.length; i < len; i++) {
-            if (predicate(array[i])) {
-                return array[i];
-            }
-        }
-        return undefined;
-    }
-
     export function indexOfAnyCharCode(text: string, charCodes: number[], start?: number): number {
         for (let i = start || 0, len = text.length; i < len; i++) {
             if (contains(charCodes, text.charCodeAt(i))) {
@@ -229,6 +220,19 @@ namespace ts {
         return true;
     }
 
+    /**
+     * Returns the first element that matches the predicate, or undefined if none
+     * could be found.
+     */
+    export function find<T>(array: T[], predicate: (item: T) => boolean): T {
+        for (let i = 0, len = array.length; i < len; i++) {
+            if (predicate(array[i])) {
+                return array[i];
+            }
+        }
+        return undefined;
+    }
+
     /**
      * Returns the last element of an array if non-empty, undefined otherwise.
      */
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 1dffc35c74c..34f5d481075 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -3033,31 +3033,31 @@
         "code": 17010
     },
     "Add missing 'super()' call.": {
-        "category": "CodeFix",
+        "category": "Message",
         "code": 90001
     },
     "Make 'super()' call the first statement in the constructor.": {
-        "category": "CodeFix",
+        "category": "Message",
         "code": 90002
     },
     "Change 'extends' to 'implements'": {
-        "category": "CodeFix",
+        "category": "Message",
         "code": 90003
     },
     "Remove unused identifiers": {
-        "category": "CodeFix",
+        "category": "Message",
         "code": 90004
     },
     "Implement interface on reference": {
-        "category": "CodeFix",
+        "category": "Message",
         "code": 90005
     },
     "Implement interface on class": {
-        "category": "CodeFix",
+        "category": "Message",
         "code": 90006
     },
     "Implement inherited abstract class": {
-        "category": "CodeFix",
+        "category": "Message",
         "code": 90007
     }
 }
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index e31a4b0ace1..28ededebb0d 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -2547,7 +2547,6 @@ namespace ts {
         Warning,
         Error,
         Message,
-        CodeFix,
     }
 
     export enum ModuleResolutionKind {
diff --git a/src/harness/fourslash.ts b/src/harness/fourslash.ts
index 91597d7f593..19fa9ba5b4a 100644
--- a/src/harness/fourslash.ts
+++ b/src/harness/fourslash.ts
@@ -1,4 +1,4 @@
-//
+//
 // Copyright (c) Microsoft Corporation.  All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
@@ -1879,11 +1879,11 @@ namespace FourSlash {
                 this.raiseError("Errors expected.");
             }
 
-            if (diagnostics.length > 1 && !errorCode) {
+            if (diagnostics.length > 1 && errorCode !== undefined) {
                 this.raiseError("When there's more than one error, you must specify the errror to fix.");
             }
 
-            const diagnostic = !errorCode ? diagnostics[0] : ts.firstOrUndefined(diagnostics, d => d.code == errorCode);
+            const diagnostic = !errorCode ? diagnostics[0] : ts.find(diagnostics, d => d.code == errorCode);
 
             const actual = this.languageService.getCodeFixesAtPosition(fileName, diagnostic.start, diagnostic.length, [`TS${diagnostic.code}`]);
 
diff --git a/src/services/codefixes/codeFixProvider.ts b/src/services/codefixes/codeFixProvider.ts
index ca877aef46a..71199af88fa 100644
--- a/src/services/codefixes/codeFixProvider.ts
+++ b/src/services/codefixes/codeFixProvider.ts
@@ -1,7 +1,6 @@
-/* @internal */
+/* @internal */
 namespace ts {
     export interface CodeFix {
-        name: string;
         errorCodes: string[];
         getCodeActions(context: CodeFixContext): CodeAction[];
     }
@@ -14,7 +13,7 @@ namespace ts {
         newLineCharacter: string;
     }
 
-    export namespace codeFix {
+    export namespace codefix {
         const codeFixes: Map<CodeFix[]> = {};
 
         export function registerCodeFix(action: CodeFix) {
@@ -37,8 +36,6 @@ namespace ts {
                 const fixes = codeFixes[context.errorCode];
                 let allActions: CodeAction[] = [];
 
-                Debug.assert(fixes && fixes.length > 0, "No fixes found for error: '${errorCode}'.");
-
                 forEach(fixes, f => {
                     const actions = f.getCodeActions(context);
                     if (actions && actions.length > 0) {
diff --git a/src/services/codefixes/references.ts b/src/services/codefixes/references.ts
index 3675d626678..a9ab7a98b33 100644
--- a/src/services/codefixes/references.ts
+++ b/src/services/codefixes/references.ts
@@ -1,6 +1,3 @@
 ///<reference path='..\services.ts' />
 ///<reference path='codeFixProvider.ts' />
 ///<reference path='superFixes.ts' />
-///<reference path='unusedIdentifierFixes.ts' />
-///<reference path='changeExtendsToImplementsFix.ts' />
-///<reference path='interfaceFixes.ts' />
diff --git a/src/services/codefixes/superFixes.ts b/src/services/codefixes/superFixes.ts
index 2c6a67de513..d06ba9df955 100644
--- a/src/services/codefixes/superFixes.ts
+++ b/src/services/codefixes/superFixes.ts
@@ -1,13 +1,12 @@
 /* @internal */
-namespace ts.codeFix {
+namespace ts.codefix {
     function getOpenBraceEnd(constructor: ConstructorDeclaration, sourceFile: SourceFile) {
         // First token is the open curly, this is where we want to put the 'super' call.
         return constructor.body.getFirstToken(sourceFile).getEnd();
     }
 
     registerCodeFix({
-        name: "AddMissingSuperCallFix",
-        errorCodes: ["TS2377"],
+        errorCodes: [`TS${Diagnostics.Constructors_for_derived_classes_must_contain_a_super_call.code}`],
         getCodeActions: (context: CodeFixContext) => {
             const sourceFile = context.sourceFile;
             const token = getTokenAtPosition(sourceFile, context.span.start);
@@ -22,8 +21,7 @@ namespace ts.codeFix {
     });
 
     registerCodeFix({
-        name: "MakeSuperCallTheFirstStatementInTheConstructor",
-        errorCodes: ["TS17009"],
+        errorCodes: [`TS${Diagnostics.super_must_be_called_before_accessing_this_in_the_constructor_of_a_derived_class.code}`],
         getCodeActions: (context: CodeFixContext) => {
             const sourceFile = context.sourceFile;
 
diff --git a/src/services/services.ts b/src/services/services.ts
index b189a6375b7..839fc4c298e 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -1902,7 +1902,7 @@ namespace ts {
     }
 
     export function getSupportedCodeFixes() {
-        return codeFix.CodeFixProvider.getSupportedErrorCodes();
+        return codefix.CodeFixProvider.getSupportedErrorCodes();
     }
 
     // Cache host information about script Should be refreshed
@@ -3041,7 +3041,7 @@ namespace ts {
         documentRegistry: DocumentRegistry = createDocumentRegistry(host.useCaseSensitiveFileNames && host.useCaseSensitiveFileNames(), host.getCurrentDirectory())): LanguageService {
 
         const syntaxTreeCache: SyntaxTreeCache = new SyntaxTreeCache(host);
-        const codeFixProvider: codeFix.CodeFixProvider = new codeFix.CodeFixProvider();
+        const codeFixProvider: codefix.CodeFixProvider = new codefix.CodeFixProvider();
         let ruleProvider: formatting.RulesProvider;
         let program: Program;
         let lastProjectVersion: string;