diff --git a/src/classes/PRunMuMinus.cpp b/src/classes/PRunMuMinus.cpp
index 244b9bb1..6ac952e3 100644
--- a/src/classes/PRunMuMinus.cpp
+++ b/src/classes/PRunMuMinus.cpp
@@ -27,6 +27,14 @@
  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  ***************************************************************************/
 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef HAVE_GOMP
+#include <omp.h>
+#endif
+
 #include <iostream>
 using namespace std;