diff --git a/emvar-lite/mod.ts b/emvar-lite/mod.ts
index 2963484..01846c4 100644
--- a/emvar-lite/mod.ts
+++ b/emvar-lite/mod.ts
@@ -87,6 +87,10 @@ export function rangeOr(...ranges: (string | Checker)[]): Checker {
     return firstCheck;
 }
 
+export function notRange(range: string | Checker): Checker {
+    return rangeOf(range).not();
+}
+
 
 export class EmVar {
     static from(range: string | EmVar): EmVar {
@@ -148,4 +152,7 @@ export class Checker {
     public or(other: Checker): Checker {
         return new Checker((value) => this.check(value) || other.check(value));
     }
+    public not(): Checker {
+        return new Checker((value) => !this.check(value));
+    }
 }
\ No newline at end of file
diff --git a/emvar-lite/range.test.ts b/emvar-lite/test.ts
similarity index 87%
rename from emvar-lite/range.test.ts
rename to emvar-lite/test.ts
index 62a1f9d..1ad79f9 100644
--- a/emvar-lite/range.test.ts
+++ b/emvar-lite/test.ts
@@ -1,6 +1,6 @@
 
 import { expect } from "https://deno.land/x/expect@v0.2.9/mod.ts";
-import { rangeAnd, rangeOf, rangeOr } from "./mod.ts";
+import { notRange, rangeAnd, rangeOf, rangeOr } from "./mod.ts";
 const { test } = Deno;
 
 
@@ -137,4 +137,24 @@ const { test } = Deno;
 
         expect(checker.check("2")).toBe(false);
     })
+}
+
+
+{
+    const checker = notRange(rangeOf('1.2.*'));
+    test(`!rangeOf(1.2.*) valid`, () => {
+        expect(checker.check("1.3")).toBe(true);
+        expect(checker.check("1.3.1")).toBe(true);
+
+        expect(checker.check("1.1.1")).toBe(true);
+        expect(checker.check("1.1")).toBe(true);
+        expect(checker.check("1")).toBe(true);
+
+
+        expect(checker.check("2")).toBe(true);
+    })
+    test(`!rangeOf(1.2.*) invalid `, () => {
+        expect(checker.check("1.2")).toBe(false);
+        expect(checker.check("1.2.1")).toBe(false);
+    })
 }
\ No newline at end of file