diff --git a/Make.inc.in b/Make.inc.in
index 3638f486..9ac10ee7 100644
--- a/Make.inc.in
+++ b/Make.inc.in
@@ -75,7 +75,7 @@ CDEFINES=$(AMGCDEFINES)
 AMGFDEFINES=@AMGFDEFINES@ $(PSBFDEFINES)
 FDEFINES=$(AMGFDEFINES)
 
-CXXDEFINES=@AMGCXXDEFINES@
+CXXDEFINES=@AMGCXXDEFINES@ $(PSBCXXDEFINES)
 
 @COMPILERULES@