diff --git a/meson.build b/meson.build
index a0fa425..7fea7c2 100644
--- a/meson.build
+++ b/meson.build
@@ -45,6 +45,12 @@
 
 conf.set('CONFIG_PHAL_API', get_option('phal').allowed())
 
+if(get_option('transport-implementation')) == 'mctp-demux'
+   add_project_arguments('-DPLDM_TRANSPORT_WITH_MCTP_DEMUX', language : 'cpp')
+else
+   add_project_arguments('-DPLDM_TRANSPORT_WITH_AF_MCTP', language: 'cpp')
+endif
+
 if cmplr.has_header('poll.h')
     add_project_arguments('-DPLDM_HAS_POLL=1', language: 'cpp')
 endif