diff --git a/src/addons/search/Interfaces.ts b/src/addons/search/Interfaces.ts
new file mode 100644
index 000000000..7a7a87cc7
--- /dev/null
+++ b/src/addons/search/Interfaces.ts
@@ -0,0 +1,19 @@
+/**
+ * Copyright (c) 2018 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { Terminal } from 'xterm';
+
+export interface ISearchAddonTerminal extends Terminal {
+  __searchHelper: ISearchHelper;
+
+  // TODO: Reuse ITerminal from core
+  buffer: any;
+  selectionManager: any;
+}
+
+export interface ISearchHelper {
+  findNext(term: string): boolean;
+  findPrevious(term: string): boolean;
+}
diff --git a/src/addons/search/SearchHelper.ts b/src/addons/search/SearchHelper.ts
index 5735dd48e..dd941682a 100644
--- a/src/addons/search/SearchHelper.ts
+++ b/src/addons/search/SearchHelper.ts
@@ -3,8 +3,7 @@
  * @license MIT
  */
 
-// import { ITerminal } from '../../Interfaces';
-// import { translateBufferLineToString } from '../../utils/BufferLine';
+import { ISearchHelper, ISearchAddonTerminal } from './Interfaces';
 
 interface ISearchResult {
   term: string;
@@ -15,8 +14,8 @@ interface ISearchResult {
 /**
  * A class that knows how to search the terminal and how to display the results.
  */
-export class SearchHelper {
-  constructor(private _terminal: any) {
+export class SearchHelper implements ISearchHelper {
+  constructor(private _terminal: ISearchAddonTerminal) {
     // TODO: Search for multiple instances on 1 line
     // TODO: Don't use the actual selection, instead use a "find selection" so multiple instances can be highlighted
     // TODO: Highlight other instances in the viewport
@@ -134,7 +133,7 @@ export class SearchHelper {
       return false;
     }
     this._terminal.selectionManager.setSelection(result.col, result.row, result.term.length);
-    this._terminal.scrollLines(result.row - this._terminal.buffer.ydisp, false);
+    this._terminal.scrollLines(result.row - this._terminal.buffer.ydisp);
     return true;
   }
 }
diff --git a/src/addons/search/search.ts b/src/addons/search/search.ts
index 473c78fcf..2f5db9224 100644
--- a/src/addons/search/search.ts
+++ b/src/addons/search/search.ts
@@ -3,8 +3,11 @@
  * @license MIT
  */
 
-import { SearchHelper } from './SearchHelper';
+/// <reference path="../../../typings/xterm.d.ts"/>
 
+import { SearchHelper } from './SearchHelper';
+import { Terminal } from 'xterm';
+import { ISearchAddonTerminal } from './Interfaces';
 
 /**
  * Find the next instance of the term, then scroll to and select it. If it
@@ -12,11 +15,12 @@ import { SearchHelper } from './SearchHelper';
  * @param term Tne search term.
  * @return Whether a result was found.
  */
-export function findNext(terminal: any, term: string): boolean {
-  if (!terminal._searchHelper) {
-    terminal.searchHelper = new SearchHelper(terminal);
+export function findNext(terminal: Terminal, term: string): boolean {
+  const addonTerminal = (<ISearchAddonTerminal>terminal);
+  if (!addonTerminal.__searchHelper) {
+    addonTerminal.__searchHelper = new SearchHelper(addonTerminal);
   }
-  return (<SearchHelper>terminal.searchHelper).findNext(term);
+  return addonTerminal.__searchHelper.findNext(term);
 }
 
 /**
@@ -25,19 +29,20 @@ export function findNext(terminal: any, term: string): boolean {
  * @param term Tne search term.
  * @return Whether a result was found.
  */
-export function findPrevious(terminal: any, term: string): boolean {
-  if (!terminal._searchHelper) {
-    terminal.searchHelper = new SearchHelper(terminal);
+export function findPrevious(terminal: Terminal, term: string): boolean {
+  const addonTerminal = (<ISearchAddonTerminal>terminal);
+  if (!addonTerminal.__searchHelper) {
+    addonTerminal.__searchHelper = new SearchHelper(addonTerminal);
   }
-  return (<SearchHelper>terminal.searchHelper).findPrevious(term);
+  return addonTerminal.__searchHelper.findPrevious(term);
 }
 
 export function apply(terminalConstructor: any): void {
-  terminalConstructor.prototype.findNext = function(term: any): boolean {
+  terminalConstructor.prototype.findNext = function(term: string): boolean {
     return findNext(this, term);
   };
 
-  terminalConstructor.prototype.findPrevious = function(term: any): boolean {
+  terminalConstructor.prototype.findPrevious = function(term: string): boolean {
     return findPrevious(this, term);
   };
 }