diff --git a/shared/utils/check_env.py b/shared/utils/check_env.py
index f9a0e89..d35d23c 100644
--- a/shared/utils/check_env.py
+++ b/shared/utils/check_env.py
@@ -11,4 +11,5 @@ def check_env(
     assert all(isinstance(elem, str) for elem in var_list)
     # check that env vars are set
     for env_var in var_list:
-        assert env_var in os.environ, f"environment variable not set: {env_var}"
+        if env_var not in os.environ:
+            raise OSError(f"environment variable not set: {env_var}")