diff --git a/docs/source/modules/datasets.rst b/docs/source/modules/datasets.rst
index 4d40443166..d5f07b5651 100644
--- a/docs/source/modules/datasets.rst
+++ b/docs/source/modules/datasets.rst
@@ -169,14 +169,14 @@ of vocabs.
      - 115
      - абвгдежзийклмнопрстуфхцчшщьюяАБВГДЕЖЗИЙКЛМНОПРСТУФХЦЧШЩЬЮЯ0123456789!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~°£€¥¢฿ґіїєҐІЇЄ₴
    * - vietnamese
-     - 236
-     - 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~°£€¥¢฿áàảạãăắằẳẵặâấầẩẫậđéèẻẽẹêếềểễệóòỏõọôốồổộỗơớờởợỡúùủũụưứừửữựiíìỉĩịýỳỷỹỵÁÀẢẠÃĂẮẰẲẴẶÂẤẦẨẪẬĐÉÈẺẼẸÊẾỀỂỄỆÓÒỎÕỌÔỐỒỔỘỖƠỚỜỞỢỠÚÙỦŨỤƯỨỪỬỮỰIÍÌỈĨỊÝỲỶỸỴ
+     - 234
+     - 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~°£€¥¢฿áàảạãăắằẳẵặâấầẩẫậđéèẻẽẹêếềểễệóòỏõọôốồổộỗơớờởợỡúùủũụưứừửữựíìỉĩịýỳỷỹỵÁÀẢẠÃĂẮẰẲẴẶÂẤẦẨẪẬĐÉÈẺẼẸÊẾỀỂỄỆÓÒỎÕỌÔỐỒỔỘỖƠỚỜỞỢỠÚÙỦŨỤƯỨỪỬỮỰÍÌỈĨỊÝỲỶỸỴ
    * - hebrew
      - 123
      - 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~°£€¥¢฿אבגדהוזחטיכלמנסעפצקרשת₪
    * - hindi
-     - 71
-     - अआइईउऊऋॠऌॡएऐओऔअंअःकखगघङचछजझञटठडढणतथदधनपफबभमयरलवशषसह०१२३४५६७८९।,?!:्ॐ॰॥॰
+     - 68
+     - अआइईउऊऋॠऌॡएऐओऔंःकखगघङचछजझञटठडढणतथदधनपफबभमयरलवशषसह०१२३४५६७८९।,?!:्ॐ॰॥
    * - bangla
      - 70
      - অআইঈউঊঋএঐওঔকখগঘঙচছজঝঞটঠডঢণতথদধনপফবভমযরলশষসহ়ঽািীুূৃেৈোৌ্ৎংঃঁ০১২৩৪৫৬৭৮৯
diff --git a/doctr/datasets/vocabs.py b/doctr/datasets/vocabs.py
index 36e5cbb4d4..f91b76d64f 100644
--- a/doctr/datasets/vocabs.py
+++ b/doctr/datasets/vocabs.py
@@ -19,9 +19,9 @@
     "arabic_digits": "٠١٢٣٤٥٦٧٨٩",
     "arabic_diacritics": "ًٌٍَُِّْ",
     "arabic_punctuation": "؟؛«»—",
-    "hindi_letters": "अआइईउऊऋॠऌॡएऐओऔअंअःकखगघङचछजझञटठडढणतथदधनपफबभमयरलवशषसह",
+    "hindi_letters": "अआइईउऊऋॠऌॡएऐओऔंःकखगघङचछजझञटठडढणतथदधनपफबभमयरलवशषसह",
     "hindi_digits": "०१२३४५६७८९",
-    "hindi_punctuation": "।,?!:्ॐ॰॥॰",
+    "hindi_punctuation": "।,?!:्ॐ॰॥",
     "bangla_letters": "অআইঈউঊঋএঐওঔকখগঘঙচছজঝঞটঠডঢণতথদধনপফবভমযরলশষসহ়ঽািীুূৃেৈোৌ্ৎংঃঁ",
     "bangla_digits": "০১২৩৪৫৬৭৮৯",
     "generic_cyrillic_letters": "абвгдежзийклмнопрстуфхцчшщьюяАБВГДЕЖЗИЙКЛМНОПРСТУФХЦЧШЩЬЮЯ",
@@ -53,8 +53,8 @@
 VOCABS["swedish"] = VOCABS["english"] + "åäöÅÄÖ"
 VOCABS["vietnamese"] = (
     VOCABS["english"]
-    + "áàảạãăắằẳẵặâấầẩẫậđéèẻẽẹêếềểễệóòỏõọôốồổộỗơớờởợỡúùủũụưứừửữựiíìỉĩịýỳỷỹỵ"
-    + "ÁÀẢẠÃĂẮẰẲẴẶÂẤẦẨẪẬĐÉÈẺẼẸÊẾỀỂỄỆÓÒỎÕỌÔỐỒỔỘỖƠỚỜỞỢỠÚÙỦŨỤƯỨỪỬỮỰIÍÌỈĨỊÝỲỶỸỴ"
+    + "áàảạãăắằẳẵặâấầẩẫậđéèẻẽẹêếềểễệóòỏõọôốồổộỗơớờởợỡúùủũụưứừửữựíìỉĩịýỳỷỹỵ"
+    + "ÁÀẢẠÃĂẮẰẲẴẶÂẤẦẨẪẬĐÉÈẺẼẸÊẾỀỂỄỆÓÒỎÕỌÔỐỒỔỘỖƠỚỜỞỢỠÚÙỦŨỤƯỨỪỬỮỰÍÌỈĨỊÝỲỶỸỴ"
 )
 VOCABS["hebrew"] = VOCABS["english"] + "אבגדהוזחטיכלמנסעפצקרשת" + "₪"
 VOCABS["hindi"] = VOCABS["hindi_letters"] + VOCABS["hindi_digits"] + VOCABS["hindi_punctuation"]
diff --git a/tests/common/test_datasets_vocabs.py b/tests/common/test_datasets_vocabs.py
new file mode 100644
index 0000000000..cd84bf7ac7
--- /dev/null
+++ b/tests/common/test_datasets_vocabs.py
@@ -0,0 +1,11 @@
+from collections import Counter
+
+from doctr.datasets import VOCABS
+
+
+def test_vocabs_duplicates():
+    for key, vocab in VOCABS.items():
+        assert isinstance(vocab, str)
+
+        duplicates = [char for char, count in Counter(vocab).items() if count > 1]
+        assert not duplicates, f"Duplicate characters in {key} vocab: {duplicates}"