diff --git a/src/ro/cui.spec.ts b/src/ro/cui.spec.ts
index 632f43a..df99378 100644
--- a/src/ro/cui.spec.ts
+++ b/src/ro/cui.spec.ts
@@ -8,6 +8,12 @@ describe('ro/cui', () => {
     expect(result).toEqual('185 472 90');
   });
 
+  it('validate:18547290 (8 digits, padded to 10 for checksum)', () => {
+    const result = validate('18547290');
+
+    expect(result.isValid).toBe(true);
+  });
+
   it('validate:185 472 90', () => {
     const result = validate('185 472 90');
 
@@ -25,4 +31,11 @@ describe('ro/cui', () => {
 
     expect(result.error).toBeInstanceOf(InvalidChecksum);
   });
+
+  it('validate:18547291 (8 digits, invalid checksum after padding)', () => {
+    const result = validate('18547291');
+
+    expect(result.isValid).toBe(false);
+    expect(result.error).toBeInstanceOf(InvalidChecksum);
+  });
 });
diff --git a/src/ro/cui.ts b/src/ro/cui.ts
index 1de4509..e285831 100644
--- a/src/ro/cui.ts
+++ b/src/ro/cui.ts
@@ -57,7 +57,10 @@ const impl: Validator = {
       return { isValid: false, error: new exceptions.InvalidFormat() };
     }
 
-    const [front, check] = strings.splitAt(value.padStart(9, '0'), -1);
+    // FIX: Pad to 10 total digits. 
+    // This ensures that 'front' is always exactly 9 digits, 
+    // perfectly matching the 9 weights provided.
+    const [front, check] = strings.splitAt(value.padStart(10, '0'), -1);
 
     const sum =
       10 *