diff --git a/keeper/.gitignore b/keeper/.gitignore
index f3364f6..76fd571 100644
--- a/keeper/.gitignore
+++ b/keeper/.gitignore
@@ -62,4 +62,7 @@ typings/
 
 # Distributive
 compiled
-*.d.ts
\ No newline at end of file
+*.d.ts
+
+# Except these
+!/__types__/*.d.ts
diff --git a/keeper/__types__/global.d.ts b/keeper/__types__/global.d.ts
new file mode 100644
index 0000000..afa75c4
--- /dev/null
+++ b/keeper/__types__/global.d.ts
@@ -0,0 +1 @@
+declare const global: any;
diff --git a/keeper/src/keeper/keeper.ts b/keeper/src/keeper/keeper.ts
index 238cb04..2fa97a5 100644
--- a/keeper/src/keeper/keeper.ts
+++ b/keeper/src/keeper/keeper.ts
@@ -1,11 +1,12 @@
 const nil = null;
 const BOLD = 'font-weight: bold;';
-const globalThis = Function('return this')() as Window & {
+type GlobalThis = Window & {
 	Date: DateConstructor;
 	perfKeeper?: {
 		system: PerfKeeper;
 	};
 };
+const globalThis = typeof window === 'undefined' ? typeof global === 'undefined' ? this : global : window as GlobalThis;
 const Date = globalThis.Date;
 
 const dateNow = Date.now;
diff --git a/performance/__types__/global.ts b/performance/__types__/global.ts
new file mode 100644
index 0000000..afa75c4
--- /dev/null
+++ b/performance/__types__/global.ts
@@ -0,0 +1 @@
+declare const global: any;
diff --git a/performance/src/performance/performance.ts b/performance/src/performance/performance.ts
index 204f936..f2eb3a2 100644
--- a/performance/src/performance/performance.ts
+++ b/performance/src/performance/performance.ts
@@ -188,7 +188,8 @@ export function polyfill<T extends object>(global: T) {
 	};
 }
 
-const globalThis = polyfill(new Function('return this'));
+const globalObject = typeof window === 'undefined' ? typeof global === 'undefined' ? this : global : window;
+const globalThis = polyfill(globalObject);
 
 if (typeof self !== 'undefined' && (self as any) !== globalThis) {
 	polyfill(self);