diff --git a/tools/test_tool_option_parsing.py b/tools/test_tool_option_parsing.py
index 5c33db6d..c1148948 100755
--- a/tools/test_tool_option_parsing.py
+++ b/tools/test_tool_option_parsing.py
@@ -368,7 +368,8 @@ def main():
     try:
         import xdist  # noqa
 
-        args += ["-n", "auto"]
+        ncores = os.environ.get("FDO_CI_CONCURRENT", "auto")
+        args += ["-n", ncores]
     except ImportError:
         logger.info("python-xdist missing, this test will be slow")
         pass