diff -Nur a/src/tests/md_openmp.f b/src/tests/md_openmp.f
--- a/src/tests/md_openmp.f	2018-03-28 18:39:54.000000000 +0800
+++ b/src/tests/md_openmp.f	2023-07-23 18:20:01.290716484 +0800
@@ -35,9 +35,9 @@
 c
 c    None
 c
-      implicit none
+      use omp_lib
 
-      include 'omp_lib.h'
+      implicit none
 
       integer nd
       parameter ( nd = 3 )