-AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_srcdir)/src \
- -DINSTALL_BIN_PATH=\""$(lttnglibexecdir)"\" \
- -DINSTALL_LIB_PATH=\""$(libdir)"\"
+AM_CPPFLAGS += -DINSTALL_BIN_PATH=\""$(lttnglibexecdir)"\" \
+ -DINSTALL_LIB_PATH=\""$(libdir)"\"
AM_CFLAGS = -fno-strict-aliasing