diff --git a/src/Makevars.in b/src/Makevars.in
index 68dfb5293..5e4ec24db 100644
--- a/src/Makevars.in
+++ b/src/Makevars.in
@@ -11,4 +11,4 @@ PKG_LIBS    = $(LAPACK_LIBS) $(BLAS_LIBS) $(FLIBS) $(SHLIB_OPENMP_CXXFLAGS) @SL@
 
 # Release options
 PKG_CFLAGS  =  -D_isrxode2_
-PKG_CXXFLAGS = $(SHLIB_OPENMP_CXXFLAGS) -D_isrxode2_ -DBOOST_DISABLE_ASSERTS -DBOOST_NO_CXX11_STATIC_ASSERT -DBOOST_PHOENIX_NO_VARIADIC_EXPRESSION -D_HAS_AUTO_PTR_ETC=0 -D_REENTRANT -@ISYSTEM@"$(BH)" -@ISYSTEM@"$(EG)" $(SH) -@ISYSTEM@"$(RCPP)"
+PKG_CXXFLAGS = $(SHLIB_OPENMP_CXXFLAGS) -D_isrxode2_ -DBOOST_DISABLE_ASSERTS -DBOOST_PHOENIX_NO_VARIADIC_EXPRESSION -D_HAS_AUTO_PTR_ETC=0 -D_REENTRANT -@ISYSTEM@"$(BH)" -@ISYSTEM@"$(EG)" $(SH) -@ISYSTEM@"$(RCPP)"