diff --git a/src/swig/nlopt-python.i b/src/swig/nlopt-python.i
index b5cf55e1..30c7ccb0 100644
--- a/src/swig/nlopt-python.i
+++ b/src/swig/nlopt-python.i
@@ -124,8 +124,10 @@ __version__ = str(_nlopt.version_major())+'.'+str(_nlopt.version_minor())+'.'+st
 {
   npy_intp sz = $1.size();
   $result = PyArray_SimpleNew(1, &sz, NPY_DOUBLE);
-  std::memcpy(array_data($result), $1.empty() ? NULL : &$1[0],
-	      sizeof(double) * sz);
+  if (!$1.empty())
+  {
+    std::memcpy(array_data($result), &$1[0], sizeof(double) * sz);
+  }
 }
 
 //////////////////////////////////////////////////////////////////////////////
diff --git a/test/cpp_functor.cxx b/test/cpp_functor.cxx
index 47168368..0ec8e423 100644
--- a/test/cpp_functor.cxx
+++ b/test/cpp_functor.cxx
@@ -100,7 +100,7 @@ class LinearRegression {
     LinearRegression(QuadraticForm quadratic_form_) :
       quadratic_form(std::move(quadratic_form_)) {}
 
-    double operator()(unsigned n, const double* x, double* grad) const
+    double operator()(unsigned /*n*/, const double* x, double* grad) const
     {
       const double result = quadratic_form.compute_form(x);
       if (!!grad) {