diff --git a/index.d.ts b/index.d.ts
index b42e4c0..b2c7213 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -68,9 +68,9 @@ export interface ColorSupport {
 }
 
 export interface Chalk {
-	(...text: string[]): string;
+	(...text: unknown[]): string;
 
-	(text: TemplateStringsArray, ...placeholders: string[]): string;
+	(text: TemplateStringsArray, ...placeholders: unknown[]): string;
 
 	/**
 	 * Return a new Chalk instance.
diff --git a/index.js.flow b/index.js.flow
index aac750e..1a3099d 100644
--- a/index.js.flow
+++ b/index.js.flow
@@ -23,7 +23,7 @@ export type ColorSupport = {|
 
 export interface Chalk {
 	(...text: string[]): string,
-	(text: TemplateStringsArray, ...placeholders: string[]): string,
+	(text: TemplateStringsArray, ...placeholders: mixed[]): string,
 	constructor(options?: Options): Chalk,
 	enabled: boolean,
 	level: Level,
diff --git a/index.test-d.ts b/index.test-d.ts
index 6cda4da..5920526 100644
--- a/index.test-d.ts
+++ b/index.test-d.ts
@@ -27,6 +27,7 @@ expectType<Level>(chalk.level);
 expectType<string>(chalk``);
 const name = 'John';
 expectType<string>(chalk`Hello {bold.red ${name}}`);
+expectType<string>(chalk`Works with numbers {bold.red ${1}}`);
 
 // -- Color methods --
 expectType<colorReturn>(chalk.hex('#DEADED'));
diff --git a/test/_flow.js b/test/_flow.js
index 2cf3cf2..ac76e85 100644
--- a/test/_flow.js
+++ b/test/_flow.js
@@ -9,10 +9,6 @@ chalk.constructor({level: 1});
 new chalk.constructor({enabled: 'true'});
 new chalk.constructor({enabled: true});
 
-// $ExpectError (Can't pass in null)
-chalk.underline(null);
-chalk.underline('foo');
-
 // $ExpectError (Can't have typo in chalk method)
 chalk.rd('foo');
 chalk.red('foo');
@@ -29,10 +25,6 @@ chalk.red.bgBlue.underline('foo');
 const badCtx = chalk.constructor({level: 4});
 const ctx = chalk.constructor({level: 3});
 
-// $ExpectError (Can't pass in null)
-ctx(null);
-ctx('foo');
-
 // $ExpectError (Can't have typo in method name)
 ctx.gry('foo');
 ctx.grey('foo');