diff --git a/DESCRIPTION b/DESCRIPTION
index c36bb8d..f5bc1e3 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: HSAR
 Title: Hierarchical Spatial Autoregressive Model
-Version: 0.6.0
+Version: 0.6.1
 Authors@R: 
     c(
       person(given = "Guanpeng", family = "Dong",
diff --git a/src/Makevars b/src/Makevars
index a6a8570..1dc52b9 100644
--- a/src/Makevars
+++ b/src/Makevars
@@ -1,4 +1,4 @@
 #PKG_CXXFLAGS = $(LAPACK_LIBS) $(BLAS_LIBS) $(FLIBS)
 #PKG_LIBS = $(LAPACK_LIBS) $(BLAS_LIBS) $(FLIBS)
-PKG_CXXFLAGS = $(SHLIB_OPENMP_CXXFLAGS)
+PKG_CXXFLAGS = $(SHLIB_OPENMP_CXXFLAGS) -DARMA_64BIT_WORD=1
 PKG_LIBS = $(SHLIB_OPENMP_CXXFLAGS) $(LAPACK_LIBS) $(BLAS_LIBS) $(FLIBS)
diff --git a/src/Makevars.win b/src/Makevars.win
index a6a8570..1dc52b9 100644
--- a/src/Makevars.win
+++ b/src/Makevars.win
@@ -1,4 +1,4 @@
 #PKG_CXXFLAGS = $(LAPACK_LIBS) $(BLAS_LIBS) $(FLIBS)
 #PKG_LIBS = $(LAPACK_LIBS) $(BLAS_LIBS) $(FLIBS)
-PKG_CXXFLAGS = $(SHLIB_OPENMP_CXXFLAGS)
+PKG_CXXFLAGS = $(SHLIB_OPENMP_CXXFLAGS) -DARMA_64BIT_WORD=1
 PKG_LIBS = $(SHLIB_OPENMP_CXXFLAGS) $(LAPACK_LIBS) $(BLAS_LIBS) $(FLIBS)