diff --git a/jqueryui/jqueryui.d.ts b/jqueryui/jqueryui.d.ts
index 42de3a3af..1a09df7fd 100644
--- a/jqueryui/jqueryui.d.ts
+++ b/jqueryui/jqueryui.d.ts
@@ -73,7 +73,7 @@ declare module JQueryUI {
     }
 
     interface Autocomplete extends Widget, AutocompleteOptions, AutocompleteEvents {
-        escapeRegex: (string) => string;
+        escapeRegex: (value: string) => string;
     }
 
 
@@ -154,7 +154,7 @@ declare module JQueryUI {
 
     interface Datepicker extends Widget, DatepickerOptions {
         regional: { [languageCod3: string]: any; };
-        setDefaults(defaults: DatepickerOptions);
+        setDefaults(defaults: DatepickerOptions): void;
         formatDate(format: string, date: Date, settings?: DatepickerFormatDateOptions): string;
         parseDate(format: string, date: string, settings?: DatepickerFormatDateOptions): Date;
         iso8601Week(date: Date): void;
diff --git a/modernizr/modernizr.d.ts b/modernizr/modernizr.d.ts
index ae02c0113..4de482aec 100644
--- a/modernizr/modernizr.d.ts
+++ b/modernizr/modernizr.d.ts
@@ -92,9 +92,9 @@ interface ModernizrStatic {
     touch: boolean;
     webgl: boolean;
 
-    load(resources: Array);
-    load(resourceObject: any);
-    load(resourceString: string);
+    load(resources: Array): void;
+    load(resourceObject: any): void;
+    load(resourceString: string): void;
 
     prefixed(): boolean;
     prefixed(property: string): boolean;
@@ -102,11 +102,11 @@ interface ModernizrStatic {
 
     mq(mediaQuery: string): boolean;
 
-    addTest(feature: string, test: () => any);
-    addTest(feature: string, test: boolean);
-    addTest(feature: any);
+    addTest(feature: string, test: () => any): void;
+    addTest(feature: string, test: boolean): void;
+    addTest(feature: any): void;
 
-    testStyles(rule: string, callback: (element, rule) => void, nodes?: number, testnames?: string[]): boolean;
+    testStyles(rule: string, callback: (element: HTMLDivElement, rule: string) => void, nodes?: number, testnames?: string[]): boolean;
     testProp(property: string): boolean;
     testAllProps(property: string, prefix?: string): boolean;
     testAllProps(property: string, obj: any, element: any): boolean;