diff --git a/config.mk.in b/config.mk.in
index b3ff89e..6e0aa0a 100644
--- a/config.mk.in
+++ b/config.mk.in
@@ -1,6 +1,6 @@
 CC = @CC@
 CFLAGS = @CFLAGS@
-CXXFLAGS = -fPIC -std=c++0x
+CXXFLAGS += -fPIC -std=c++0x
 SQLPP = @SQLPP@
 
 XML2_CPPFLAGS = @XML2_CPPFLAGS@