diff --git a/puremd_rc_1003/sPuReMD/mytypes.h b/puremd_rc_1003/sPuReMD/mytypes.h
index 8a20d56cb24ca29eb8a0541006435e5d41109000..fefe6e6f3fb645b95f9593f1c7202c6db196b9d0 100644
--- a/puremd_rc_1003/sPuReMD/mytypes.h
+++ b/puremd_rc_1003/sPuReMD/mytypes.h
@@ -31,6 +31,10 @@
 #include "time.h"
 #include "zlib.h"
 
+#ifdef _OPENMP
+#include <omp.h>
+#endif
+
 //#define DEBUG_FOCUS
 //#define TEST_FORCES
 //#define TEST_ENERGY