diff --git a/R/Makevars b/R/Makevars
index ef965ed7..6f7d0c42 100644
--- a/R/Makevars
+++ b/R/Makevars
@@ -88,8 +88,7 @@ OBJECTS.phreeqcpp = \
 
 OBJECTS = $(OBJECTS.root) $(OBJECTS.phreeqcpp)
 
-PKG_CPPFLAGS =-I. -Iphreeqcpp -DNDEBUG -DR_SO -DSWIG_SHARED_OBJ -DVAR_UNION_NAME=u -pedantic
-##PKG_CPPFLAGS =-I. -Iphreeqcpp -DNDEBUG -DR_SO -DSWIG_SHARED_OBJ -pedantic
+PKG_CPPFLAGS =-I. -Iphreeqcpp -DNDEBUG -DR_SO -DSWIG_SHARED_OBJ
 
 all: $(SHLIB)