diff --git a/gulp-if/gulp-if.d.ts b/gulp-if/gulp-if.d.ts
index d73fa52e7..474682b9d 100644
--- a/gulp-if/gulp-if.d.ts
+++ b/gulp-if/gulp-if.d.ts
@@ -6,6 +6,9 @@
 /// <reference path="../node/node.d.ts"/>
 
 declare module "gulp-if" {
-    function gulpIf(condition: boolean, stream: NodeJS.ReadWriteStream, elseStream?: NodeJS.ReadWriteStream): NodeJS.ReadWriteStream;
+    function gulpIf(
+        condition: boolean,
+        stream: NodeJS.ReadWriteStream,
+        elseStream?: NodeJS.ReadWriteStream): NodeJS.ReadWriteStream;
     export = gulpIf;
 }
\ No newline at end of file
diff --git a/gulp-istanbul/gulp-istanbul.d.ts b/gulp-istanbul/gulp-istanbul.d.ts
index 4b03b16a6..bf7a13bb0 100644
--- a/gulp-istanbul/gulp-istanbul.d.ts
+++ b/gulp-istanbul/gulp-istanbul.d.ts
@@ -10,7 +10,7 @@ declare module "gulp-istanbul" {
 
     module GulpIstanbul {
         export function hookRequire(): NodeJS.ReadWriteStream;
-        export function summarizeCoverage(opts?: {coverageVariable: string}): Coverage;
+        export function summarizeCoverage(opts?: {coverageVariable?: string}): Coverage;
         export function writeReports(opts?: ReportOptions): NodeJS.ReadWriteStream;
 
         interface Options {
diff --git a/gulp-rename/gulp-rename.d.ts b/gulp-rename/gulp-rename.d.ts
index 7b8960007..18a3f5ffb 100644
--- a/gulp-rename/gulp-rename.d.ts
+++ b/gulp-rename/gulp-rename.d.ts
@@ -6,15 +6,19 @@
 /// <reference path="../node/node.d.ts"/>
 
 declare module "gulp-rename" {
-    interface Options {
+    interface ParsedPath {
         dirname?: string;
         basename?: string;
-        prefix?: string;
-        suffix?: string;
         extname?: string;
     }
+
+    interface Options extends ParsedPath {
+        prefix?: string;
+        suffix?: string;
+    }
+
     function rename(name: string): NodeJS.ReadWriteStream;
-    function rename(callback: (path: Options) => any): NodeJS.ReadWriteStream;
+    function rename(callback: (path: ParsedPath) => any): NodeJS.ReadWriteStream;
     function rename(opts: Options): NodeJS.ReadWriteStream;
     export = rename;
 }
\ No newline at end of file
diff --git a/gulp-replace/gulp-replace.d.ts b/gulp-replace/gulp-replace.d.ts
index fb352ea9a..6607da98c 100644
--- a/gulp-replace/gulp-replace.d.ts
+++ b/gulp-replace/gulp-replace.d.ts
@@ -7,7 +7,7 @@
 
 declare module "gulp-replace" {
     interface Options {
-        skipBinary: boolean;
+        skipBinary?: boolean;
     }
 
     function replace(pattern: string, replacement: string, opts?: Options): NodeJS.ReadWriteStream;
diff --git a/gulp-tslint/gulp-tslint.d.ts b/gulp-tslint/gulp-tslint.d.ts
index 423625ea0..afae9efa3 100644
--- a/gulp-tslint/gulp-tslint.d.ts
+++ b/gulp-tslint/gulp-tslint.d.ts
@@ -13,7 +13,7 @@ declare module "gulp-tslint" {
 
     module GulpTsLint {
         interface Options {
-            configuration?: Object;
+            configuration?: {};
             rulesDirectory?: string;
             emitError?: boolean;
         }