diff --git a/lib/threads/Threads.h b/lib/threads/Threads.h
index 36daf2af..dacaf5d8 100644
--- a/lib/threads/Threads.h
+++ b/lib/threads/Threads.h
@@ -40,7 +40,7 @@ Author: paboyle <paboyle@ph.ed.ac.uk>
 
 #define PARALLEL_FOR_LOOP        _Pragma("omp parallel for schedule(static)")
 #define PARALLEL_FOR_LOOP_INTERN _Pragma("omp for schedule(static)")
-#define PARALLEL_NESTED_LOOP2 _Pragma("omp parallel for collapse(2)")
+#define PARALLEL_NESTED_LOOP2 _Pragma("omp parallel for schedule(static) collapse(2)")
 #define PARALLEL_REGION       _Pragma("omp parallel")
 #define PARALLEL_CRITICAL     _Pragma("omp critical")
 #else