diff --git a/Project_Model/Libs/Transformer/Utils/inference_masking.py b/Project_Model/Libs/Transformer/Utils/inference_masking.py
new file mode 100644
index 0000000..4dc4345
--- /dev/null
+++ b/Project_Model/Libs/Transformer/Utils/inference_masking.py
@@ -0,0 +1,13 @@
+def inference_masking(sequence: list[int], mask_token: int, max_vocabulary: int) -> list[int]:
+
+    current_mask_token = max_vocabulary + 1
+
+    for i in range(0, len(sequence)):
+
+        if sequence[i] != mask_token:
+            continue
+
+        sequence[i] = current_mask_token
+        current_mask_token += 1
+
+    return sequence