diff --git a/dev-requirements.txt b/dev-requirements.txt
index e079f8a..3d2f598 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -1 +1 @@
-pytest
+pytest>=9.0.2,<10
diff --git a/requirements-ocr.txt b/requirements-ocr.txt
index 1cce72d..5be5e13 100644
--- a/requirements-ocr.txt
+++ b/requirements-ocr.txt
@@ -1,14 +1,14 @@
 # Optional OCR dependencies
 
 # traditional OCR
-pillow
-pytesseract
-opencv-python
-tqdm
-streamlit
-python-Levenshtein
+pillow>=12.1.0,<13
+pytesseract>=0.3.13,<1
+opencv-python>=4.13.0.90,<5
+tqdm>=4.67.2,<5
+streamlit>=1.53.1,<2
+python-Levenshtein>=0.27.3,<1
 
 # ocr with keras/tensorflow
-tensorflow
-keras
-matplotlib
\ No newline at end of file
+tensorflow>=2.20.0,<3
+keras>=3.13.2,<4
+matplotlib>=3.10.8,<4
\ No newline at end of file
diff --git a/requirements.txt b/requirements.txt
index 5e89b6e..695d533 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,9 +1,9 @@
 # data acquisition and web scraping
-selenium
-beautifulsoup4
+selenium>=4.40.0,<5
+beautifulsoup4>=4.14.3,<5
 
 # audio processing
-openai-whisper
+openai-whisper>=20250625,<20260000
 
 # for sending results to webhook
-requests
+requests>=2.32.5,<3