-lib${mod}_plugin_la_CFLAGS = \$(AM_CFLAGS)
-lib${mod}_plugin_la_CXXFLAGS = \$(AM_CXXFLAGS)
-lib${mod}_plugin_la_OBJCFLAGS = \$(AM_OBJCFLAGS)
+lib${mod}_plugin_la_CPPFLAGS = \$(AM_CPPFLAGS) \$(CPPFLAGS_${mod})
+lib${mod}_plugin_la_CFLAGS = \$(AM_CFLAGS) \$(CFLAGS_${mod})
+lib${mod}_plugin_la_CXXFLAGS = \$(AM_CXXFLAGS) \$(CXXFLAGS_${mod})
+lib${mod}_plugin_la_OBJCFLAGS = \$(AM_OBJCFLAGS) \$(OBJCFLAGS_${mod})