diff --git a/setup.py b/setup.py
index 6619048..b35fafa 100644
--- a/setup.py
+++ b/setup.py
@@ -11,7 +11,7 @@ module_pEp = Extension('pEp',
         include_dirs = [prefix+'/include', boost+'/include',],
         library_dirs = [prefix+'/lib', boost+'/lib',],
         libraries = ['pEpEngine', 'boost_python-mt', 'boost_locale-mt',],
-        extra_compile_args = ['-O0', '-g',],
+        extra_compile_args = ['-O0', '-UNDEBUG',],
     )
 
 setup(
diff --git a/src/sync_mixin.cc b/src/sync_mixin.cc
index 70f3fe0..bda136a 100644
--- a/src/sync_mixin.cc
+++ b/src/sync_mixin.cc
@@ -55,9 +55,9 @@ namespace pEp {
         }
 
 #ifndef NDEBUG
-        virtual void _inject(int event, Identity *partner, object extra)
+        void SyncMixIn::_inject(int event, Identity *partner, object extra)
         {
-            PEP_SESSION session = fsm_DeviceState_inject(session,
+            PEP_STATUS status = fsm_DeviceState_inject(session,
                     (DeviceState_event) event, partner->detach(), NULL);
         }
 #endif