diff --git a/Detectors/Base/src/Stack.cxx b/Detectors/Base/src/Stack.cxx
index e7caca2982318..cf80c45d3d11c 100644
--- a/Detectors/Base/src/Stack.cxx
+++ b/Detectors/Base/src/Stack.cxx
@@ -101,7 +101,7 @@ Stack::Stack(Int_t size)
     transportPrimary = o2::conf::GetFromMacro<o2::data::Stack::TransportFcn>(param.transportPrimaryFileName,
                                                                              param.transportPrimaryFuncName,
                                                                              "o2::data::Stack::TransportFcn", "stack_transport_primary");
-    if (!mTransportPrimary) {
+    if (!transportPrimary) {
       LOG(fatal) << "Failed to retrieve external \'transportPrimary\' function: problem with configuration ";
     }
     LOG(info) << "Successfully retrieve external \'transportPrimary\' frunction: " << param.transportPrimaryFileName;
@@ -110,7 +110,7 @@ Stack::Stack(Int_t size)
   }
 
   if (param.transportPrimaryInvert) {
-    mTransportPrimary = [transportPrimary](const TParticle& p, const std::vector<TParticle>& particles) { return !transportPrimary; };
+    mTransportPrimary = [transportPrimary](const TParticle& p, const std::vector<TParticle>& particles) { return !transportPrimary(p, particles); };
   } else {
     mTransportPrimary = transportPrimary;
   }