diff --git a/docs/rules/semicolon/index.html b/docs/rules/semicolon/index.html
index 8b62432c4b1..095bfb1ee96 100644
--- a/docs/rules/semicolon/index.html
+++ b/docs/rules/semicolon/index.html
@@ -9,7 +9,6 @@
   * `"never"` disallows semicolons at the end of every statement except for when they are necessary.
 
   The following arguments may be optionaly provided:
-
   * `"ignore-interfaces"` skips checking semicolons at the end of interface members.
   * `"ignore-bound-class-methods"` skips checking semicolons at the end of bound class methods.
 options:
@@ -52,4 +51,4 @@
     ],
     "additionalItems": false
   }
----
+---
\ No newline at end of file
diff --git a/src/language/rule/abstractRule.ts b/src/language/rule/abstractRule.ts
index 3d7f7aed9ec..242562560d3 100644
--- a/src/language/rule/abstractRule.ts
+++ b/src/language/rule/abstractRule.ts
@@ -17,7 +17,8 @@
 
 import * as ts from "typescript";
 
-import {RuleWalker} from "../walker/ruleWalker";
+import {doesIntersect} from "../utils";
+import {IWalker} from "../walker";
 import {IDisabledInterval, IOptions, IRule, IRuleMetadata, RuleFailure} from "./rule";
 
 export abstract class AbstractRule implements IRule {
@@ -36,7 +37,7 @@ export abstract class AbstractRule implements IRule {
         return false;
     }
 
-    constructor(ruleName: string, private value: any, disabledIntervals: IDisabledInterval[]) {
+    constructor(ruleName: string, private value: any, private disabledIntervals: IDisabledInterval[]) {
         let ruleArguments: any[] = [];
 
         if (Array.isArray(value) && value.length > 1) {
@@ -56,12 +57,23 @@ export abstract class AbstractRule implements IRule {
 
     public abstract apply(sourceFile: ts.SourceFile, languageService: ts.LanguageService): RuleFailure[];
 
-    public applyWithWalker(walker: RuleWalker): RuleFailure[] {
+    public applyWithWalker(walker: IWalker): RuleFailure[] {
         walker.walk(walker.getSourceFile());
-        return walker.getFailures();
+        return this.filterFailures(walker.getFailures());
     }
 
     public isEnabled(): boolean {
         return AbstractRule.isRuleEnabled(this.value);
     }
+
+    protected filterFailures(failures: RuleFailure[]): RuleFailure[] {
+        const result: RuleFailure[] = [];
+        for (const failure of failures) {
+            // don't add failures for a rule if the failure intersects an interval where that rule is disabled
+            if (!doesIntersect(failure, this.disabledIntervals) && !result.some((f) => f.equals(failure))) {
+                result.push(failure);
+            }
+        }
+        return result;
+    }
 }
diff --git a/src/language/rule/rule.ts b/src/language/rule/rule.ts
index 5e969b3710e..16ae16950d8 100644
--- a/src/language/rule/rule.ts
+++ b/src/language/rule/rule.ts
@@ -17,7 +17,7 @@
 
 import * as ts from "typescript";
 
-import {RuleWalker} from "../walker/ruleWalker";
+import {IWalker} from "../walker";
 
 export interface IRuleMetadata {
     /**
@@ -96,7 +96,7 @@ export interface IRule {
     getOptions(): IOptions;
     isEnabled(): boolean;
     apply(sourceFile: ts.SourceFile, languageService: ts.LanguageService): RuleFailure[];
-    applyWithWalker(walker: RuleWalker): RuleFailure[];
+    applyWithWalker(walker: IWalker): RuleFailure[];
 }
 
 export class Replacement {
diff --git a/src/language/utils.ts b/src/language/utils.ts
index 6a17f363acb..826283e904b 100644
--- a/src/language/utils.ts
+++ b/src/language/utils.ts
@@ -196,3 +196,36 @@ export function unwrapParentheses(node: ts.Expression) {
     }
     return node;
 }
+
+export function isScopeBoundary(node: ts.Node): boolean {
+    return node.kind === ts.SyntaxKind.FunctionDeclaration
+        || node.kind === ts.SyntaxKind.FunctionExpression
+        || node.kind === ts.SyntaxKind.PropertyAssignment
+        || node.kind === ts.SyntaxKind.ShorthandPropertyAssignment
+        || node.kind === ts.SyntaxKind.MethodDeclaration
+        || node.kind === ts.SyntaxKind.Constructor
+        || node.kind === ts.SyntaxKind.ModuleDeclaration
+        || node.kind === ts.SyntaxKind.ArrowFunction
+        || node.kind === ts.SyntaxKind.ParenthesizedExpression
+        || node.kind === ts.SyntaxKind.ClassDeclaration
+        || node.kind === ts.SyntaxKind.ClassExpression
+        || node.kind === ts.SyntaxKind.InterfaceDeclaration
+        || node.kind === ts.SyntaxKind.GetAccessor
+        || node.kind === ts.SyntaxKind.SetAccessor
+        || node.kind === ts.SyntaxKind.SourceFile && ts.isExternalModule(node as ts.SourceFile);
+}
+
+export function isBlockScopeBoundary(node: ts.Node): boolean {
+    return isScopeBoundary(node)
+        || node.kind === ts.SyntaxKind.Block
+        || node.kind === ts.SyntaxKind.DoStatement
+        || node.kind === ts.SyntaxKind.WhileStatement
+        || node.kind === ts.SyntaxKind.ForStatement
+        || node.kind === ts.SyntaxKind.ForInStatement
+        || node.kind === ts.SyntaxKind.ForOfStatement
+        || node.kind === ts.SyntaxKind.WithStatement
+        || node.kind === ts.SyntaxKind.SwitchStatement
+        || node.parent !== undefined
+            && (node.parent.kind === ts.SyntaxKind.TryStatement
+            || node.parent.kind === ts.SyntaxKind.IfStatement);
+}
diff --git a/src/language/walker/blockScopeAwareRuleWalker.ts b/src/language/walker/blockScopeAwareRuleWalker.ts
index 75f862ee61a..185ab14e723 100644
--- a/src/language/walker/blockScopeAwareRuleWalker.ts
+++ b/src/language/walker/blockScopeAwareRuleWalker.ts
@@ -17,6 +17,7 @@
 
 import * as ts from "typescript";
 
+import {isBlockScopeBoundary} from "../utils";
 import {ScopeAwareRuleWalker} from "./scopeAwareRuleWalker";
 
 /**
@@ -30,7 +31,7 @@ export abstract class BlockScopeAwareRuleWalker<T, U> extends ScopeAwareRuleWalk
         super(sourceFile, options);
 
         // initialize with global scope if file is not a module
-        this.blockScopeStack = this.fileIsModule ? [] : [this.createBlockScope(sourceFile)];
+        this.blockScopeStack = ts.isExternalModule(sourceFile) ? [] : [this.createBlockScope(sourceFile)];
     }
 
     public abstract createBlockScope(node: ts.Node): U;
@@ -85,20 +86,6 @@ export abstract class BlockScopeAwareRuleWalker<T, U> extends ScopeAwareRuleWalk
     }
 
     private isBlockScopeBoundary(node: ts.Node): boolean {
-        return super.isScopeBoundary(node)
-            || node.kind === ts.SyntaxKind.Block
-            || node.kind === ts.SyntaxKind.DoStatement
-            || node.kind === ts.SyntaxKind.WhileStatement
-            || node.kind === ts.SyntaxKind.ForStatement
-            || node.kind === ts.SyntaxKind.ForInStatement
-            || node.kind === ts.SyntaxKind.ForOfStatement
-            || node.kind === ts.SyntaxKind.WithStatement
-            || node.kind === ts.SyntaxKind.SwitchStatement
-            || isParentKind(node, ts.SyntaxKind.TryStatement)
-            || isParentKind(node, ts.SyntaxKind.IfStatement);
+        return isBlockScopeBoundary(node);
     }
 }
-
-function isParentKind(node: ts.Node, kind: ts.SyntaxKind) {
-    return node.parent != null && node.parent.kind === kind;
-}
diff --git a/src/language/walker/index.ts b/src/language/walker/index.ts
index b762aa289ed..bf1ab5df58b 100644
--- a/src/language/walker/index.ts
+++ b/src/language/walker/index.ts
@@ -21,3 +21,4 @@ export * from "./ruleWalker";
 export * from "./scopeAwareRuleWalker";
 export * from "./skippableTokenAwareRuleWalker";
 export * from "./syntaxWalker";
+export * from "./walker";
diff --git a/src/language/walker/ruleWalker.ts b/src/language/walker/ruleWalker.ts
index 0f98f2e41cc..bc43d53c058 100644
--- a/src/language/walker/ruleWalker.ts
+++ b/src/language/walker/ruleWalker.ts
@@ -17,26 +17,22 @@
 
 import * as ts from "typescript";
 
-import {Fix, IDisabledInterval, IOptions, Replacement, RuleFailure} from "../rule/rule";
-import {doesIntersect} from "../utils";
+import {Fix, IOptions, Replacement, RuleFailure} from "../rule/rule";
 import {SyntaxWalker} from "./syntaxWalker";
+import {IWalker} from "./walker";
 
-export class RuleWalker extends SyntaxWalker {
+export class RuleWalker extends SyntaxWalker implements IWalker {
     private limit: number;
-    private position: number;
     private options?: any[];
     private failures: RuleFailure[];
-    private disabledIntervals: IDisabledInterval[];
     private ruleName: string;
 
     constructor(private sourceFile: ts.SourceFile, options: IOptions) {
         super();
 
-        this.position = 0;
         this.failures = [];
         this.options = options.ruleArguments;
         this.limit = this.sourceFile.getFullWidth();
-        this.disabledIntervals = options.disabledIntervals;
         this.ruleName = options.ruleName;
     }
 
@@ -68,8 +64,8 @@ export class RuleWalker extends SyntaxWalker {
         }
     }
 
-    public skip(node: ts.Node) {
-        this.position += node.getFullWidth();
+    public skip(_node: ts.Node) {
+        return; // TODO remove this method in next major version
     }
 
     public createFailure(start: number, width: number, failure: string, fix?: Fix): RuleFailure {
@@ -79,10 +75,7 @@ export class RuleWalker extends SyntaxWalker {
     }
 
     public addFailure(failure: RuleFailure) {
-        // don't add failures for a rule if the failure intersects an interval where that rule is disabled
-        if (!this.existsFailure(failure) && !doesIntersect(failure, this.disabledIntervals)) {
-            this.failures.push(failure);
-        }
+        this.failures.push(failure);
     }
 
     /** Add a failure with any arbitrary span. Prefer `addFailureAtNode` if possible. */
@@ -97,7 +90,7 @@ export class RuleWalker extends SyntaxWalker {
 
     /** Add a failure using a node's span. */
     public addFailureAtNode(node: ts.Node, failure: string, fix?: Fix) {
-        this.addFailureAt(node.getStart(), node.getWidth(), failure, fix);
+        this.addFailureAt(node.getStart(this.sourceFile), node.getWidth(this.sourceFile), failure, fix);
     }
 
     public createReplacement(start: number, length: number, text: string): Replacement {
@@ -112,7 +105,11 @@ export class RuleWalker extends SyntaxWalker {
         return this.createReplacement(start, length, "");
     }
 
-    private existsFailure(failure: RuleFailure) {
-        return this.failures.some((f) => f.equals(failure));
+    public getRuleName(): string {
+        return this.ruleName;
+    }
+
+    public createFix(replacements: Replacement[]): Fix {
+        return new Fix(this.ruleName, replacements);
     }
 }
diff --git a/src/language/walker/scopeAwareRuleWalker.ts b/src/language/walker/scopeAwareRuleWalker.ts
index aa01d4af19e..d7ab2d002d3 100644
--- a/src/language/walker/scopeAwareRuleWalker.ts
+++ b/src/language/walker/scopeAwareRuleWalker.ts
@@ -17,19 +17,17 @@
 
 import * as ts from "typescript";
 
+import {isScopeBoundary} from "../utils";
 import {RuleWalker} from "./ruleWalker";
 
 export abstract class ScopeAwareRuleWalker<T> extends RuleWalker {
-    protected fileIsModule: boolean;
     private scopeStack: T[];
 
     constructor(sourceFile: ts.SourceFile, options?: any) {
         super(sourceFile, options);
 
-        this.fileIsModule = ts.isExternalModule(sourceFile);
-
         // initialize with global scope if file is not a module
-        this.scopeStack = this.fileIsModule ? [] : [this.createScope(sourceFile)];
+        this.scopeStack = ts.isExternalModule(sourceFile) ? [] : [this.createScope(sourceFile)];
     }
 
     public abstract createScope(node: ts.Node): T;
@@ -40,7 +38,7 @@ export abstract class ScopeAwareRuleWalker<T> extends RuleWalker {
 
     // get all scopes available at this depth
     public getAllScopes(): T[] {
-        return this.scopeStack.slice();
+        return this.scopeStack;
     }
 
     public getCurrentDepth(): number {
@@ -74,20 +72,6 @@ export abstract class ScopeAwareRuleWalker<T> extends RuleWalker {
     }
 
     protected isScopeBoundary(node: ts.Node): boolean {
-        return node.kind === ts.SyntaxKind.FunctionDeclaration
-            || node.kind === ts.SyntaxKind.FunctionExpression
-            || node.kind === ts.SyntaxKind.PropertyAssignment
-            || node.kind === ts.SyntaxKind.ShorthandPropertyAssignment
-            || node.kind === ts.SyntaxKind.MethodDeclaration
-            || node.kind === ts.SyntaxKind.Constructor
-            || node.kind === ts.SyntaxKind.ModuleDeclaration
-            || node.kind === ts.SyntaxKind.ArrowFunction
-            || node.kind === ts.SyntaxKind.ParenthesizedExpression
-            || node.kind === ts.SyntaxKind.ClassDeclaration
-            || node.kind === ts.SyntaxKind.ClassExpression
-            || node.kind === ts.SyntaxKind.InterfaceDeclaration
-            || node.kind === ts.SyntaxKind.GetAccessor
-            || node.kind === ts.SyntaxKind.SetAccessor
-            || (node.kind === ts.SyntaxKind.SourceFile && this.fileIsModule);
+        return isScopeBoundary(node);
     }
 }
diff --git a/src/language/walker/walker.ts b/src/language/walker/walker.ts
new file mode 100644
index 00000000000..3c07585e418
--- /dev/null
+++ b/src/language/walker/walker.ts
@@ -0,0 +1,26 @@
+/**
+ * @license
+ * Copyright 2017 Palantir Technologies, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as ts from "typescript";
+
+import {RuleFailure} from "../rule/rule";
+
+export interface IWalker {
+    getSourceFile(): ts.SourceFile;
+    walk(node: ts.Node): void;
+    getFailures(): RuleFailure[];
+}