diff --git a/pyomo/contrib/parmest/examples/reactor_design/parameter_estimation_example.py b/pyomo/contrib/parmest/examples/reactor_design/parameter_estimation_example.py
index a84a3fde5e7..d29cbfd4d49 100644
--- a/pyomo/contrib/parmest/examples/reactor_design/parameter_estimation_example.py
+++ b/pyomo/contrib/parmest/examples/reactor_design/parameter_estimation_example.py
@@ -39,3 +39,7 @@ def main():
     obj, theta, cov = pest.theta_est(calc_cov=True, cov_n=17)
     print(obj)
     print(theta)
+
+
+if __name__ == "__main__":
+    main()