diff --git a/gst/modplug/Makefile.am b/gst/modplug/Makefile.am
index a784ddd315..bdf7d56f38 100644
--- a/gst/modplug/Makefile.am
+++ b/gst/modplug/Makefile.am
@@ -5,7 +5,7 @@ plugindir = $(libdir)/gstreamer-@GST_MAJORMINOR@
 plugin_LTLIBRARIES = libgstmodplug.la
 
 libgstmodplug_la_SOURCES = modplug_types.cc gstmodplug.cc
-libgstmodplug_la_CPPFLAGS = $(GST_CFLAGS)
+libgstmodplug_la_CXXFLAGS = $(GST_CFLAGS)
 libgstmodplug_la_LIBADD = $(top_builddir)/gst/modplug/libmodplug/libmodplug.la
 libgstmodplug_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)