diff --git a/packages/compiler/src/aot/static_reflector.ts b/packages/compiler/src/aot/static_reflector.ts
index 3e67872937..d699cd6210 100644
--- a/packages/compiler/src/aot/static_reflector.ts
+++ b/packages/compiler/src/aot/static_reflector.ts
@@ -132,7 +132,7 @@ export class StaticReflector implements CompileReflector {
 
   public tryAnnotations(type: StaticSymbol): any[] {
     const originalRecorder = this.errorRecorder;
-    this.errorRecorder = (error: any, fileName: string) => {};
+    this.errorRecorder = (error: any, fileName?: string) => {};
     try {
       return this.annotations(type);
     } finally {
@@ -429,7 +429,7 @@ export class StaticReflector implements CompileReflector {
    */
   private trySimplify(context: StaticSymbol, value: any): any {
     const originalRecorder = this.errorRecorder;
-    this.errorRecorder = (error: any, fileName: string) => {};
+    this.errorRecorder = (error: any, fileName?: string) => {};
     const result = this.simplify(context, value);
     this.errorRecorder = originalRecorder;
     return result;
diff --git a/packages/compiler/src/constant_pool.ts b/packages/compiler/src/constant_pool.ts
index e0124efa9f..ff88cbca79 100644
--- a/packages/compiler/src/constant_pool.ts
+++ b/packages/compiler/src/constant_pool.ts
@@ -273,11 +273,11 @@ class KeyVisitor implements o.ExpressionVisitor {
   visitCommaExpr = invalid;
 }
 
-function invalid<T>(arg: o.Expression | o.Statement): never {
+function invalid<T>(this: o.ExpressionVisitor, arg: o.Expression | o.Statement): never {
   throw new Error(
       `Invalid state: Visitor ${this.constructor.name} doesn't handle ${arg.constructor.name}`);
 }
 
 function isVariable(e: o.Expression): e is o.ReadVarExpr {
   return e instanceof o.ReadVarExpr;
-}
\ No newline at end of file
+}
diff --git a/packages/compiler/src/jit_compiler_facade.ts b/packages/compiler/src/jit_compiler_facade.ts
index c14a4680bf..9255851376 100644
--- a/packages/compiler/src/jit_compiler_facade.ts
+++ b/packages/compiler/src/jit_compiler_facade.ts
@@ -210,7 +210,7 @@ const USE_FACTORY = Object.keys({useFactory: null})[0];
 const USE_VALUE = Object.keys({useValue: null})[0];
 const USE_EXISTING = Object.keys({useExisting: null})[0];
 
-const wrapReference = function(value: Type): R3Reference {
+const wrapReference = function(value: any): R3Reference {
   const wrapped = new WrappedNodeExpr(value);
   return {value: wrapped, type: wrapped};
 };
diff --git a/packages/compiler/src/metadata_resolver.ts b/packages/compiler/src/metadata_resolver.ts
index 5f98425f8f..6c2f2d6fff 100644
--- a/packages/compiler/src/metadata_resolver.ts
+++ b/packages/compiler/src/metadata_resolver.ts
@@ -83,7 +83,7 @@ export class CompileMetadataResolver {
 
   private _createProxyClass(baseType: any, name: string): cpl.ProxyClass {
     let delegate: any = null;
-    const proxyClass: cpl.ProxyClass = <any>function() {
+    const proxyClass: cpl.ProxyClass = <any>function(this: unknown) {
       if (!delegate) {
         throw new Error(
             `Illegal state: Class ${name} for type ${stringify(baseType)} is not compiled yet!`);
diff --git a/packages/compiler/src/ml_parser/ast.ts b/packages/compiler/src/ml_parser/ast.ts
index a94d7c02b1..2eb23de344 100644
--- a/packages/compiler/src/ml_parser/ast.ts
+++ b/packages/compiler/src/ml_parser/ast.ts
@@ -112,7 +112,7 @@ export class RecursiveVisitor implements Visitor {
       if (children) results.push(visitAll(t, children, context));
     }
     cb(visit);
-    return [].concat.apply([], results);
+    return Array.prototype.concat.apply([], results);
   }
 }
 
@@ -149,4 +149,4 @@ export function findNode(nodes: Node[], position: number): HtmlAstPath {
   visitAll(visitor, nodes);
 
   return new AstPath<Node>(path, position);
-}
\ No newline at end of file
+}
diff --git a/packages/compiler/src/output/output_interpreter.ts b/packages/compiler/src/output/output_interpreter.ts
index 7f63f7bb6c..9f25155809 100644
--- a/packages/compiler/src/output/output_interpreter.ts
+++ b/packages/compiler/src/output/output_interpreter.ts
@@ -38,8 +38,8 @@ class _ExecutionContext {
   exports: string[] = [];
 
   constructor(
-      public parent: _ExecutionContext|null, public instance: any, public className: string|null,
-      public vars: Map<string, any>) {}
+      public parent: _ExecutionContext|null, public instance: Object|null,
+      public className: string|null, public vars: Map<string, any>) {}
 
   createChildWihtLocalVars(): _ExecutionContext {
     return new _ExecutionContext(this, this.instance, this.className, new Map<string, any>());
@@ -79,9 +79,9 @@ function createDynamicClass(
 
   const ctorParamNames = _classStmt.constructorMethod.params.map(param => param.name);
   // Note: use `function` instead of arrow function to capture `this`
-  const ctor = function(...args: any[]) {
+  const ctor = function(this: Object, ...args: any[]) {
     const instanceCtx = new _ExecutionContext(_ctx, this, _classStmt.name, _ctx.vars);
-    _classStmt.fields.forEach((field) => { this[field.name] = undefined; });
+    _classStmt.fields.forEach((field) => { (this as any)[field.name] = undefined; });
     _executeFunctionStatements(
         ctorParamNames, args, _classStmt.constructorMethod.body, instanceCtx, _visitor);
   };
@@ -125,7 +125,7 @@ class StatementInterpreter implements o.StatementVisitor, o.ExpressionVisitor {
     if (ast.builtin != null) {
       switch (ast.builtin) {
         case o.BuiltinVar.Super:
-          return ctx.instance.__proto__;
+          return Object.getPrototypeOf(ctx.instance);
         case o.BuiltinVar.This:
           return ctx.instance;
         case o.BuiltinVar.CatchError:
@@ -188,7 +188,7 @@ class StatementInterpreter implements o.StatementVisitor, o.ExpressionVisitor {
     const args = this.visitAllExpressions(stmt.args, ctx);
     const fnExpr = stmt.fn;
     if (fnExpr instanceof o.ReadVarExpr && fnExpr.builtin === o.BuiltinVar.Super) {
-      ctx.instance.constructor.prototype.constructor.apply(ctx.instance, args);
+      ctx.instance !.constructor.prototype.constructor.apply(ctx.instance, args);
       return null;
     } else {
       const fn = stmt.fn.visitExpression(this, ctx);
diff --git a/packages/compiler/src/render3/view/i18n/meta.ts b/packages/compiler/src/render3/view/i18n/meta.ts
index 1c2ec9b39a..e798d9a8b9 100644
--- a/packages/compiler/src/render3/view/i18n/meta.ts
+++ b/packages/compiler/src/render3/view/i18n/meta.ts
@@ -15,7 +15,7 @@ import {ParseTreeResult} from '../../../ml_parser/parser';
 
 import {I18N_ATTR, I18N_ATTR_PREFIX, I18nMeta, hasI18nAttrs, icuFromI18nMessage, metaFromI18nMessage, parseI18nMeta} from './util';
 
-function setI18nRefs(html: html.Node & {i18n: i18n.AST}, i18n: i18n.Node) {
+function setI18nRefs(html: html.Node & {i18n?: i18n.AST}, i18n: i18n.Node) {
   html.i18n = i18n;
 }
 
@@ -128,4 +128,4 @@ export function processI18nMeta(
           new I18nMetaVisitor(interpolationConfig, /* keepI18nAttrs */ false),
           htmlAstWithErrors.rootNodes),
       htmlAstWithErrors.errors);
-}
\ No newline at end of file
+}
diff --git a/packages/compiler/src/render3/view/i18n/util.ts b/packages/compiler/src/render3/view/i18n/util.ts
index c700c1beb8..970c40be6d 100644
--- a/packages/compiler/src/render3/view/i18n/util.ts
+++ b/packages/compiler/src/render3/view/i18n/util.ts
@@ -165,7 +165,8 @@ export function assembleBoundTextPlaceholders(
       meta instanceof i18n.Message ? meta.nodes.find(node => node instanceof i18n.Container) : meta;
   if (node) {
     (node as i18n.Container)
-        .children.filter((child: i18n.Node) => child instanceof i18n.Placeholder)
+        .children
+        .filter((child: i18n.Node): child is i18n.Placeholder => child instanceof i18n.Placeholder)
         .forEach((child: i18n.Placeholder, idx: number) => {
           const content = wrapI18nPlaceholder(startIdx + idx, contextId);
           updatePlaceholderMap(placeholders, child.name, content);
diff --git a/packages/compiler/src/render3/view/template.ts b/packages/compiler/src/render3/view/template.ts
index 12dec412a2..7ed51f60b3 100644
--- a/packages/compiler/src/render3/view/template.ts
+++ b/packages/compiler/src/render3/view/template.ts
@@ -177,7 +177,7 @@ export class TemplateDefinitionBuilder implements t.Visitor<void>, LocalResolver
     this._valueConverter = new ValueConverter(
         constantPool, () => this.allocateDataSlot(),
         (numSlots: number) => this.allocatePureFunctionSlots(numSlots),
-        (name, localName, slot, value: o.ReadVarExpr) => {
+        (name, localName, slot, value: o.Expression) => {
           const pipeType = pipeTypeByName.get(name);
           if (pipeType) {
             this.pipes.add(pipeType);
@@ -1517,7 +1517,7 @@ const SHARED_CONTEXT_KEY = '$$shared_ctx$$';
  * declaration should always come before the local ref declaration.
  */
 type BindingData = {
-  retrievalLevel: number; lhs: o.ReadVarExpr; declareLocalCallback?: DeclareLocalVarCallback;
+  retrievalLevel: number; lhs: o.Expression; declareLocalCallback?: DeclareLocalVarCallback;
   declare: boolean;
   priority: number;
   localRef: boolean;
@@ -1593,7 +1593,7 @@ export class BindingScope implements LocalResolver {
    * @param declareLocalCallback The callback to invoke when declaring this local var
    * @param localRef Whether or not this is a local ref
    */
-  set(retrievalLevel: number, name: string, lhs: o.ReadVarExpr,
+  set(retrievalLevel: number, name: string, lhs: o.Expression,
       priority: number = DeclarationPriority.DEFAULT,
       declareLocalCallback?: DeclareLocalVarCallback, localRef?: true): BindingScope {
     if (this.map.has(name)) {
@@ -1644,12 +1644,14 @@ export class BindingScope implements LocalResolver {
     if (!this.map.has(bindingKey)) {
       this.generateSharedContextVar(retrievalLevel);
     }
-    return this.map.get(bindingKey) !.lhs;
+    // Shared context variables are always generated as "ReadVarExpr".
+    return this.map.get(bindingKey) !.lhs as o.ReadVarExpr;
   }
 
   getSharedContextName(retrievalLevel: number): o.ReadVarExpr|null {
     const sharedCtxObj = this.map.get(SHARED_CONTEXT_KEY + retrievalLevel);
-    return sharedCtxObj && sharedCtxObj.declare ? sharedCtxObj.lhs : null;
+    // Shared context variables are always generated as "ReadVarExpr".
+    return sharedCtxObj && sharedCtxObj.declare ? sharedCtxObj.lhs as o.ReadVarExpr : null;
   }
 
   maybeGenerateSharedContextVar(value: BindingData) {
diff --git a/packages/compiler/src/render3/view/util.ts b/packages/compiler/src/render3/view/util.ts
index 068d09d487..84b9d323bc 100644
--- a/packages/compiler/src/render3/view/util.ts
+++ b/packages/compiler/src/render3/view/util.ts
@@ -62,14 +62,14 @@ export function temporaryAllocator(statements: o.Statement[], name: string): ()
 }
 
 
-export function unsupported(feature: string): never {
+export function unsupported(this: void|Function, feature: string): never {
   if (this) {
     throw new Error(`Builder ${this.constructor.name} doesn't support ${feature} yet`);
   }
   throw new Error(`Feature ${feature} is not supported yet`);
 }
 
-export function invalid<T>(arg: o.Expression | o.Statement | t.Node): never {
+export function invalid<T>(this: t.Visitor, arg: o.Expression | o.Statement | t.Node): never {
   throw new Error(
       `Invalid state: Visitor ${this.constructor.name} doesn't handle ${arg.constructor.name}`);
 }
diff --git a/packages/compiler/src/template_parser/template_ast.ts b/packages/compiler/src/template_parser/template_ast.ts
index 7f6672c55b..4041aedd72 100644
--- a/packages/compiler/src/template_parser/template_ast.ts
+++ b/packages/compiler/src/template_parser/template_ast.ts
@@ -359,7 +359,7 @@ export class RecursiveTemplateAstVisitor extends NullTemplateVisitor implements
       if (children && children.length) results.push(templateVisitAll(t, children, context));
     }
     cb(visit);
-    return [].concat.apply([], results);
+    return Array.prototype.concat.apply([], results);
   }
 }