diff --git a/backend/requirements.txt b/backend/requirements.txt
index 44086e63db..ba8cbbfc07 100644
--- a/backend/requirements.txt
+++ b/backend/requirements.txt
@@ -52,8 +52,8 @@ chromadb==1.1.0
 weaviate-client==4.17.0
 opensearch-py==2.8.0
 
-transformers
-sentence-transformers==5.1.1
+transformers==4.57.3
+sentence-transformers==5.1.2
 accelerate
 pyarrow==20.0.0 # fix: pin pyarrow version to 20 for rpi compatibility #15897
 einops==0.8.1 
diff --git a/pyproject.toml b/pyproject.toml
index 94f5abc3c9..709f4ec672 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -60,8 +60,8 @@ dependencies = [
     "PyMySQL==1.1.1",
     "boto3==1.40.5",
     
-    "transformers",
-    "sentence-transformers==5.1.1",
+    "transformers==4.57.3",
+    "sentence-transformers==5.1.2",
     "accelerate",
     "pyarrow==20.0.0",
     "einops==0.8.1",