diff --git a/src/vs/vscode.proposed.d.ts b/src/vs/vscode.proposed.d.ts
index 6dcc58cc6dfa78761d182e1fe108085e8dc3d465..cd04e4a88a9fe65a43282be08387670ae997bfbb 100644
--- a/src/vs/vscode.proposed.d.ts
+++ b/src/vs/vscode.proposed.d.ts
@@ -189,12 +189,45 @@ declare module 'vscode' {
 		provideTextSearchResults?(query: TextSearchQuery, options: TextSearchOptions, progress: Progress<TextSearchResult>, token: CancellationToken): Thenable<void>;
 	}
 
+	/**
+	 * Options that can be set on a findTextInFiles search.
+	 */
 	export interface FindTextInFilesOptions {
+		/**
+		 * A [glob pattern](#GlobPattern) that defines the files to search for. The glob pattern
+		 * will be matched against the file paths of files relative to their workspace. Use a [relative pattern](#RelativePattern)
+		 * to restrict the search results to a [workspace folder](#WorkspaceFolder).
+		 */
 		include?: GlobPattern;
-		exclude?: GlobPattern;
+
+		/**
+		 * A [glob pattern](#GlobPattern) that defines files and folders to exclude. The glob pattern
+		 * will be matched against the file paths of resulting matches relative to their workspace. When `undefined` only default excludes will
+		 * apply, when `null` no excludes will apply.
+		 */
+		exclude?: GlobPattern | null;
+
+		/**
+		 * The maximum number of results to search for
+		 */
 		maxResults?: number;
+
+		/**
+		 * Whether external files that exclude files, like .gitignore, should be respected.
+		 * See the vscode setting `"search.useIgnoreFiles"`.
+		 */
 		useIgnoreFiles?: boolean;
+
+		/**
+		 * Whether symlinks should be followed while searching.
+		 * See the vscode setting `"search.followSymlinks"`.
+		 */
 		followSymlinks?: boolean;
+
+		/**
+		 * Interpret files using this encoding.
+		 * See the vscode setting `"files.encoding"`
+		 */
 		encoding?: string;
 	}
 
@@ -210,6 +243,24 @@ declare module 'vscode' {
 		 */
 		export function registerSearchProvider(scheme: string, provider: SearchProvider): Disposable;
 
+
+		/**
+		 * Search text in files across all [workspace folders](#workspace.workspaceFolders) in the workspace.
+		 * @param query The query parameters for the search - the search string, whether it's case-sensitive, or a regex, or matches whole words.
+		 * @param callback A callback, called for each result
+		 * @param token A token that can be used to signal cancellation to the underlying search engine.
+		 * @return A thenable that resolves when the search is complete.
+		 */
+		export function findTextInFiles(query: TextSearchQuery, callback: (result: TextSearchResult) => void, token?: CancellationToken): Thenable<void>;
+
+		/**
+		 * Search text in files across all [workspace folders](#workspace.workspaceFolders) in the workspace.
+		 * @param query The query parameters for the search - the search string, whether it's case-sensitive, or a regex, or matches whole words.
+		 * @param options An optional set of query options. Include and exclude patterns, maxResults, etc.
+		 * @param callback A callback, called for each result
+		 * @param token A token that can be used to signal cancellation to the underlying search engine.
+		 * @return A thenable that resolves when the search is complete.
+		 */
 		export function findTextInFiles(query: TextSearchQuery, options: FindTextInFilesOptions, callback: (result: TextSearchResult) => void, token?: CancellationToken): Thenable<void>;
 	}
 
diff --git a/src/vs/workbench/api/node/extHost.api.impl.ts b/src/vs/workbench/api/node/extHost.api.impl.ts
index eea4190baedd577ad17e122f0b48e3b1c15ef95b..41d84006f0f32625e7b1eecdbaaea9c5d2faccd5 100644
--- a/src/vs/workbench/api/node/extHost.api.impl.ts
+++ b/src/vs/workbench/api/node/extHost.api.impl.ts
@@ -500,7 +500,19 @@ export function createApiFactory(
 			findFiles: (include, exclude, maxResults?, token?) => {
 				return extHostWorkspace.findFiles(typeConverters.GlobPattern.from(include), typeConverters.GlobPattern.from(exclude), maxResults, extension.id, token);
 			},
-			findTextInFiles: (query: vscode.TextSearchQuery, options: vscode.FindTextInFilesOptions, callback: (result: vscode.TextSearchResult) => void, token?: vscode.CancellationToken) => {
+			findTextInFiles: (query: vscode.TextSearchQuery, optionsOrCallback, callbackOrToken?, token?: vscode.CancellationToken) => {
+				let options: vscode.FindTextInFilesOptions;
+				let callback: (result: vscode.TextSearchResult) => void;
+
+				if (typeof optionsOrCallback === 'object') {
+					options = optionsOrCallback;
+					callback = callbackOrToken;
+				} else {
+					options = {};
+					callback = optionsOrCallback;
+					token = callbackOrToken;
+				}
+
 				return extHostWorkspace.findTextInFiles(query, options || {}, callback, extension.id, token);
 			},
 			saveAll: (includeUntitled?) => {