diff --git a/Sample/Material/MaterialUtils.cpp b/Sample/Material/MaterialUtils.cpp
index 9f5fbea8c950d52c492c6a9411701de51e7caa36..432c40b12213f784c51706274865fefe4a3708e9 100644
--- a/Sample/Material/MaterialUtils.cpp
+++ b/Sample/Material/MaterialUtils.cpp
@@ -32,6 +32,8 @@ const SpinMatrix Pauli_Z(1, 0, 0, -1);
 
 } // namespace
 
+#ifndef USER_API
+
 template <typename T>
 SpinMatrix MaterialUtils::MagnetizationCorrection(complex_t unit_factor, double magnetic_factor,
                                                   Vec3<T> polarization)
@@ -49,6 +51,8 @@ template SpinMatrix MaterialUtils::MagnetizationCorrection(complex_t unit_factor
 template SpinMatrix MaterialUtils::MagnetizationCorrection(complex_t unit_factor,
                                                            double magnetic_factor, C3 polarization);
 
+#endif // USER_API
+
 complex_t MaterialUtils::ScalarReducedPotential(complex_t n, R3 k, double n_ref)
 {
     return n * n - n_ref * n_ref * R3Util::sin2Theta(k);
diff --git a/Sample/StandardSamples/FeNiBilayerBuilder.cpp b/Sample/StandardSamples/FeNiBilayerBuilder.cpp
index cb0a618ec679179f13dba677b82e97e31c9da430..645d9127e5c9812182f920de635e0774b61334bc 100644
--- a/Sample/StandardSamples/FeNiBilayerBuilder.cpp
+++ b/Sample/StandardSamples/FeNiBilayerBuilder.cpp
@@ -85,6 +85,9 @@ public:
         return *this;
     }
 };
+
+#ifndef USER_API
+
 //! Creates the sample demonstrating an Fe-Ni Bilayer with and without roughness
 //! @ingroup standard_samples
 class FeNiBilayer {
@@ -159,6 +162,8 @@ std::unique_ptr<MultiLayer> FeNiBilayer::constructSample()
     return sample;
 }
 
+#endif // USER_API
+
 MultiLayer* ExemplarySamples::createFeNiBilayer()
 {
     auto sample = FeNiBilayer{Options()};