diff --git a/AP_Periph/wscript b/AP_Periph/wscript
index 7b4bff4..bdc0c4e 100644
--- a/AP_Periph/wscript
+++ b/AP_Periph/wscript
@@ -34,6 +34,7 @@ def build(bld):
         'USE_USER_HELPERS=1',
         'CANARD_ENABLE_DEADLINE=1',
         'CANARD_MULTI_IFACE=1',
+        'CANARD_ALLOCATE_SEM=1'
         ]
     bld.env.INCLUDES += [bld.srcnode.find_dir('../AP_Periph').abspath()]