diff --git a/include/Likelihood.hpp b/include/Likelihood.hpp
index 15c4ed6..69d2c85 100644
--- a/include/Likelihood.hpp
+++ b/include/Likelihood.hpp
@@ -124,7 +124,11 @@ class LL_WOR21 : public Likelihood<T> {
     for (size_t i = 0; i < num_ecs; ++i) {
 	for (size_t j = 0; j < n_targets; ++j) {
 	    if (alignment(i, j)) {
+#if defined(MSWEEP_OPENMP_SUPPORT) && (MSWEEP_OPENMP_SUPPORT) == 1
 		local_counts[omp_get_thread_num()].inc((size_t)((size_t)alignment.get_groups()[j]*num_ecs) + i);
+#else
+		local_counts[0].inc((size_t)((size_t)alignment.get_groups()[j]*num_ecs) + i);
+#endif
 	    }
 	}
     }