diff --git a/src/ModelTree.cc b/src/ModelTree.cc
index 1f823ec1365a69ebbab7da1e501077bea1697d46..a0b0d53320aba7fc0527b09ce1c838c144467d51 100644
--- a/src/ModelTree.cc
+++ b/src/ModelTree.cc
@@ -1998,6 +1998,8 @@ ModelTree::initializeMEXCompilationWorkers(int numworkers, const filesystem::pat
           {
             lk.unlock();
             int r {system(cmd.c_str())};
+            if (r)
+              cout << cmd.c_str() << endl;
             lk.lock();
             mex_compilation_ongoing.erase(output);
             if (r)