diff --git a/Validator.ts b/Validator.ts
index bb77032..35a786f 100644
--- a/Validator.ts
+++ b/Validator.ts
@@ -26,7 +26,7 @@ export type Schema = { [key: string]: Validatable } | {
 export async function validate(
   value: any,
   validators: Validatable,
-): Promise<ValidationError[] | undefined> {
+): Promise<ValidationError[]> {
   if (instanceofValidatorArray(validators) || instanceofValidator(validators)) {
     return validateValue(value, validators);
   } else {
diff --git a/mod.ts b/mod.ts
index 3bcac77..e1fd508 100644
--- a/mod.ts
+++ b/mod.ts
@@ -6,5 +6,6 @@ export {
   Validatable,
   ArraySymbol,
 } from "./Validator.ts";
-export * from "./validators/string.ts";
-export * from "./validators/number.ts";
+export { isString } from "./validators/string.ts";
+export { isNumber, isInteger } from "./validators/number.ts";
+export { or } from "./validators/logic.ts";
diff --git a/validators/logic.test.ts b/validators/logic.test.ts
new file mode 100644
index 0000000..cf80128
--- /dev/null
+++ b/validators/logic.test.ts
@@ -0,0 +1,27 @@
+import { or } from "./logic.ts";
+import { validate, Validator, isString, isInteger } from "../mod.ts";
+import {
+  assertEquals,
+  assertNotEquals,
+} from "https://deno.land/std@0.53.0/testing/asserts.ts";
+
+Deno.test("or (match)", async () => {
+  const values: [any, Validator[]][] = [
+    ["", [isString, isInteger]],
+    [1, [isString, isInteger]],
+  ];
+  for (const [value, validators] of values) {
+    assertEquals(await validate(value, or(...validators)), []);
+  }
+});
+
+Deno.test("or (no match)", async () => {
+  const values: [any, Validator[]][] = [
+    [true, [isString, isInteger]],
+    [3.1415, [isString, isInteger]],
+    [1, [isString]],
+  ];
+  for (const [value, validators] of values) {
+    assertNotEquals(await validate(value, or(...validators)), []);
+  }
+});
diff --git a/validators/logic.ts b/validators/logic.ts
new file mode 100644
index 0000000..97153f5
--- /dev/null
+++ b/validators/logic.ts
@@ -0,0 +1,18 @@
+import { Validator, Args, Validatable, validate } from "../mod.ts";
+
+export function or(...funcs: Validatable[]): Validator {
+  return {
+    type: "or",
+    check: async (value: any) => {
+      const errors = await Promise.all(funcs.map((x) => validate(value, x)));
+      if (errors.every((x) => x.length > 0)) {
+        return {
+          errors,
+        };
+      }
+    },
+    message: (value: any, args?: Args) => {
+      return "At least one of the rules has to be successful.";
+    },
+  };
+}