diff --git a/previewer_code/setup.py b/previewer_code/setup.py
index 6ca29d6..34a6892 100644
--- a/previewer_code/setup.py
+++ b/previewer_code/setup.py
@@ -21,7 +21,7 @@ setup(
     include_package_data=True,
     install_requires=[
         'indico>=3.0.dev0',
-        'pygments',
+        'Pygments>=2.7.2,<3',
     ],
     python_requires='~=3.9',
     entry_points={'indico.plugins': {'previewer_code = indico_previewer_code:CodePreviewerPlugin'}}
diff --git a/vc_vidyo/setup.py b/vc_vidyo/setup.py
index c78d1b2..a0bc9ee 100644
--- a/vc_vidyo/setup.py
+++ b/vc_vidyo/setup.py
@@ -21,7 +21,7 @@ setup(
     include_package_data=True,
     install_requires=[
         'indico>=3.0.dev0',
-        'zeep',
+        'zeep>=4.0.0,<5',
     ],
     python_requires='~=3.9',
     classifiers=[