diff --git a/backend/requirements.txt b/backend/requirements.txt
index a389957..aa411b5 100644
--- a/backend/requirements.txt
+++ b/backend/requirements.txt
@@ -22,7 +22,7 @@ pymupdf>=1.27.2.3               # PDF parsing (cos_verifier.py, ai_engine.py)
 # ── Machine learning / NLP ────────────────────────────────────────────────────
 scikit-learn>=1.9.0           # TF-IDF cosine similarity (ai_engine.py, cos_verifier.py)
 numpy>=2.4.6
-sentence-transformers>=5.5.1    # optional: semantic embeddings (cos_verifier.py)
+sentence-transformers>=5.6.0    # optional: semantic embeddings (cos_verifier.py)
                               # falls back to TF-IDF when not installed
 
 # ── Database ──────────────────────────────────────────────────────────────────