diff --git a/src/Terminal.ts b/src/Terminal.ts
index c1fd1e7e..06a1a316 100644
--- a/src/Terminal.ts
+++ b/src/Terminal.ts
@@ -29,7 +29,7 @@ import * as Mouse from './utils/Mouse';
 import { CHARSETS } from './Charsets';
 import { getRawByteCoords } from './utils/Mouse';
 import { translateBufferLineToString } from './utils/BufferLine';
-import { CustomKeyEventHandler, Charset, LinkMatcherHandler, LinkMatcherValidationCallback, CharData, LineData } from './Types';
+import { CustomKeyEventHandler, Charset, LinkMatcherHandler, LinkMatcherValidationCallback, CharData, LineData, Option, StringOption, BooleanOption, StringArrayOption, NumberOption, GeometryOption, HandlerOption } from './Types';
 import { ITerminal, IBrowser, ITerminalOptions, IInputHandlingTerminal, ILinkMatcherOptions } from './Interfaces';
 
 // Declare for RequireJS in loadAddon
@@ -415,7 +415,13 @@ export class Terminal extends EventEmitter implements ITerminal, IInputHandlingT
    * Retrieves an option's value from the terminal.
    * @param {string} key The option key.
    */
-  public getOption(key: string): any {
+  public getOption(key: StringOption): string;
+  public getOption(key: BooleanOption): boolean;
+  public getOption(key: StringArrayOption): number[];
+  public getOption(key: NumberOption): number;
+  public getOption(key: GeometryOption): [number, number];
+  public getOption(key: HandlerOption): (data: string) => void;
+  public getOption(key: Option): any {
     if (!(key in DEFAULT_OPTIONS)) {
       throw new Error('No option with key "' + key + '"');
     }
@@ -432,8 +438,13 @@ export class Terminal extends EventEmitter implements ITerminal, IInputHandlingT
    * @param {string} key The option key.
    * @param {any} value The option value.
    */
-  public setOption(key: string, value: any): void {
-    // TODO: Give value a better type (boolean | string, ...)
+  public setOption(key: StringOption, value: string): void;
+  public setOption(key: BooleanOption, value: boolean): void;
+  public setOption(key: StringArrayOption, value: number[]): void;
+  public setOption(key: NumberOption, value: number): void;
+  public setOption(key: GeometryOption, value: [number, number]): void;
+  public setOption(key: HandlerOption, value: (data: string) => void): void;
+  public setOption(key: Option, value: any): void {
     if (!(key in DEFAULT_OPTIONS)) {
       throw new Error('No option with key "' + key + '"');
     }
diff --git a/src/Types.ts b/src/Types.ts
index 0753d80e..0de78d52 100644
--- a/src/Types.ts
+++ b/src/Types.ts
@@ -18,3 +18,26 @@ export type Charset = {[key: string]: string};
 
 export type CharData = [number, string, number];
 export type LineData = CharData[];
+
+export type Option = BooleanOption | StringOption | StringArrayOption | NumberOption | GeometryOption | HandlerOption;
+export type BooleanOption =
+    'cancelEvents' |
+    'convertEol' |
+    'cursorBlink' |
+    'debug' |
+    'disableStdin' |
+    'popOnBell' |
+    'screenKeys' |
+    'useFlowControl' |
+    'visualBell';
+export type StringOption =
+    'cursorStyle' |
+    'termName';
+export type StringArrayOption = 'colors';
+export type NumberOption =
+    'cols' |
+    'rows' |
+    'tabStopWidth' |
+    'scrollback';
+export type GeometryOption = 'geometry';
+export type HandlerOption = 'handler';