diff --git a/src/is-valid-license-plate/is-valid-license-plate.test.ts b/src/is-valid-license-plate/is-valid-license-plate.test.ts
index aaf43cb..dbed518 100644
--- a/src/is-valid-license-plate/is-valid-license-plate.test.ts
+++ b/src/is-valid-license-plate/is-valid-license-plate.test.ts
@@ -42,17 +42,22 @@ describe("isValidLicensePlate", () => {
 		});
 	});
 
-	describe("should return true", () => {
-		it("when brazilian license plate format is valid", () => {
-			expect(isValidLicensePlate("abc1234")).toBe(true);
-			expect(isValidLicensePlate("ABC1234")).toBe(true);
-			expect(isValidLicensePlate("abc-1234")).toBe(true);
-			expect(isValidLicensePlate("ABC-1234")).toBe(true);
-		});
-
-		it("when mercosul license plate format is valid", () => {
-			expect(isValidLicensePlate("abc1d23")).toBe(true);
-			expect(isValidLicensePlate("ABC1D23")).toBe(true);
+  describe("should return true", () => {
+    it("when brazilian license plate format is valid", () => {
+      expect(isValidLicensePlate("abc1234")).toBe(true);
+      expect(isValidLicensePlate("ABC1234")).toBe(true);
+      expect(isValidLicensePlate("abc-1234")).toBe(true);
+      expect(isValidLicensePlate("ABC-1234")).toBe(true);
+    });
+
+    it("when mercosul license plate format is valid", () => {
+      // Placas de Carro Mercosul (Letra na 5ª posição)
+      expect(isValidLicensePlate("abc1d23")).toBe(true);
+      expect(isValidLicensePlate("ABC1D23")).toBe(true);
+      
+      // Placas de Moto Mercosul (Letra na 6ª posição) - ADICIONE ESTAS LINHAS:
+      expect(isValidLicensePlate("ABC12D3")).toBe(true);
+      expect(isValidLicensePlate("abc12d3")).toBe(true);
 		});
 	});
 });
diff --git a/src/is-valid-license-plate/is-valid-license-plate.ts b/src/is-valid-license-plate/is-valid-license-plate.ts
index 80334f9..bdb77bc 100644
--- a/src/is-valid-license-plate/is-valid-license-plate.ts
+++ b/src/is-valid-license-plate/is-valid-license-plate.ts
@@ -1,4 +1,4 @@
-const mercosulRegex = /^[a-z]{3}[0-9]{1}[a-z]{1}[0-9]{2}$/i;
+const mercosulRegex = /^[a-z]{3}[0-9]{1}[a-z]{1}[0-9]{2}$|^[a-z]{3}[0-9]{2}[a-z]{1}[0-9]{1}$/i;
 
 const brazilianLicensePlateRegex = /^[a-z]{3}-?[0-9]{4}$/i;