diff --git a/types/resize-observer-browser/index.d.ts b/types/resize-observer-browser/index.d.ts
index 83291fe4a0..5e585f81e5 100644
--- a/types/resize-observer-browser/index.d.ts
+++ b/types/resize-observer-browser/index.d.ts
@@ -4,6 +4,12 @@
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.7
 
+declare global {
+    interface Window {
+        ResizeObserver: typeof ResizeObserver;
+    }
+}
+
 export class ResizeObserver {
     constructor(callback: ResizeObserverCallback);
     disconnect(): void;
@@ -11,7 +17,7 @@ export class ResizeObserver {
     unobserve(target: Element): void;
 }
 
-export type ResizeObserverCallback = (entries: ResizeObserverEntry[]) => void;
+export type ResizeObserverCallback = (entries: ReadonlyArray<ResizeObserverEntry>) => void;
 
 export interface ResizeObserverEntry {
     readonly target: Element;
diff --git a/types/resize-observer-browser/test/resize-observer-browser-global.tests.ts b/types/resize-observer-browser/test/resize-observer-browser-global.tests.ts
new file mode 100644
index 0000000000..6398b979fe
--- /dev/null
+++ b/types/resize-observer-browser/test/resize-observer-browser-global.tests.ts
@@ -0,0 +1,11 @@
+function resizeObserverCreatesViaWindow(): void {
+    const resizeObserver = new window.ResizeObserver((entries) => {
+        const div = document.getElementById('display-div')!;
+        const rect = entries[0].contentRect;
+        div.textContent = `${rect.left} ${rect.right}`;
+    });
+    const div = document.getElementById('resized-div')!;
+    resizeObserver.observe(div);
+    resizeObserver.unobserve(div);
+    resizeObserver.disconnect();
+}
diff --git a/types/resize-observer-browser/resize-observer-browser-tests.ts b/types/resize-observer-browser/test/resize-observer-browser-module.tests.ts
similarity index 100%
rename from types/resize-observer-browser/resize-observer-browser-tests.ts
rename to types/resize-observer-browser/test/resize-observer-browser-module.tests.ts
diff --git a/types/resize-observer-browser/tsconfig.json b/types/resize-observer-browser/tsconfig.json
index 849758c836..69a030695e 100644
--- a/types/resize-observer-browser/tsconfig.json
+++ b/types/resize-observer-browser/tsconfig.json
@@ -19,6 +19,7 @@
     },
     "files": [
         "index.d.ts",
-        "resize-observer-browser-tests.ts"
+        "test/resize-observer-browser-global.tests.ts",
+        "test/resize-observer-browser-module.tests.ts"
     ]
 }