diff --git a/.github/workflows/pythonbuild.yml b/.github/workflows/pythonbuild.yml
index b18cdc229a..f56caffc0d 100644
--- a/.github/workflows/pythonbuild.yml
+++ b/.github/workflows/pythonbuild.yml
@@ -417,7 +417,8 @@ jobs:
           cd plugins/${{ matrix.plugin-names }}
           uv pip install --system .
           if [ -f dev-requirements.in ]; then uv pip install --system -r dev-requirements.in; fi
-          uv pip install --system -U $GITHUB_WORKSPACE
+          # TODO: move to protobuf>=5. Github issue: https://github.com/flyteorg/flyte/issues/5448
+          uv pip install --system -U $GITHUB_WORKSPACE "protobuf<5"
           uv pip freeze
       - name: Test with coverage
         run: |
diff --git a/dev-requirements.in b/dev-requirements.in
index 7f42851061..ca37177df7 100644
--- a/dev-requirements.in
+++ b/dev-requirements.in
@@ -37,7 +37,12 @@ torch; python_version<'3.12'
 # Once a solution is found, this should be updated to support Windows as well.
 python-magic; (platform_system=='Darwin' or platform_system=='Linux')
 
-types-protobuf
+# Google released a new major version of the protobuf library and once that started being used in the ecosystem at large,
+# including `googleapis-common-protos` we started seeing errors in CI, so let's constrain that for now.
+# The issue to support protobuf 5 is being tracked in https://github.com/flyteorg/flyte/issues/5448.
+protobuf<5
+types-protobuf<5
+
 types-croniter
 types-decorator
 types-mock