diff --git a/tools/mace_tools.py b/tools/mace_tools.py
index 347f2f750d2e224a9da71361c6a0a7d2237cf3da..5d19070479baee225466ef6cfd742803353cccdd 100644
--- a/tools/mace_tools.py
+++ b/tools/mace_tools.py
@@ -386,8 +386,8 @@ def parse_args():
         help="Enable out of range check for opencl.")
     parser.add_argument(
         "--enable_openmp",
-        type="bool",
-        default="true",
+        type=str2bool,
+        default=True,
         help="Enable openmp.")
     parser.add_argument(
         "--omp_num_threads",