diff --git a/src/make.inc b/src/make.inc
index 2ba3d6b135da8c1627da9b0e5504c6c266cc8777..962471f05863f79b4e84ace15e994e6e29fbc8a4 100644
--- a/src/make.inc
+++ b/src/make.inc
@@ -74,6 +74,9 @@ endif
 # CXXFLAGS defines the default compilation options for the C++ compiler
 ifndef CXXFLAGS
 override CXXFLAGS=-O3 -ggdb -pg -coverage -I$(HDF5_INCLUDE)
+ifdef USE_OPENMP
+override CXXFLAGS+= -fopenmp
+endif
 ifdef USE_LAPACK
 override CXXFLAGS+= -DUSE_LAPACK -DLAPACK_ILP64 
 ifdef USE_MKL