diff --git a/pyproject.toml b/pyproject.toml
index 9f6cfae6c..30156025a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,7 +9,7 @@ readme = "README.md"
 [tool.poetry.dependencies]
 python = "^3.9,<3.15"                                               # 3.9 is needed for pandas
 pyserial = "^3.5"
-protobuf = ">=4.21.12"
+protobuf = ">=4.21.12,<5"
 tabulate = "^0.9.0"
 requests = "^2.31.0"
 pyyaml = "^6.0.1"