diff --git a/omnn/math/test/ActivationFunctionTests.cpp b/omnn/math/test/ActivationFunctionTests.cpp
new file mode 100644
index 000000000..e9f061d25
--- /dev/null
+++ b/omnn/math/test/ActivationFunctionTests.cpp
@@ -0,0 +1,61 @@
+#define BOOST_TEST_MODULE TestRelu test
+#include <boost/test/unit_test.hpp>
+
+#include <omnn/math/pi.h>
+#include <omnn/math/Variable.h>
+
+#include <iostream>
+#include <cmath>
+#include <cassert>
+
+using namespace omnn::math;
+using namespace boost::unit_test;
+
+
+// ReLU activation function
+auto relu(auto x) {
+    return std::max(x, {});
+}
+// Tanh activation function
+auto tanh_activation(auto x) {
+    return std::tanh(x);
+}
+// GELU activation function
+auto gelu(const Valuable& x) {
+    return x / constants::two * (constants::one + std::tanh((2 / constants::pi).sqrt() * (x + 0.044715 * (x ^ 3))));
+}
+
+BOOST_AUTO_TEST_CASE(test_relu)
+{
+    BOOST_TEST(relu(constants::zero).IsZero());
+    BOOST_TEST(relu(constants::one) == constants::one);
+    BOOST_TEST(relu(constants::minus_1).IsZero());
+    BOOST_TEST(relu(10_v) == 10_v);
+    BOOST_TEST(relu(-10_v).IsZero());
+}
+
+BOOST_AUTO_TEST_CASE(test_tanh
+                     , *disabled()
+                     ) {
+    BOOST_TEST(std::abs(tanh_activation(constants::zero).IsZero());
+    BOOST_TEST(static_cast<double>(std::abs(tanh_activation(constants::one)) - 0.761594) < 1e-6);
+    BOOST_TEST(static_cast<double>(std::abs(tanh_activation(constants::minus_1) +0.761594) < 1e-6);
+    BOOST_TEST(std::abs(tanh_activation(10_v) - constants::one).IsZero());
+    BOOST_TEST(std::abs(tanh_activation(-10_v) - constants::one).IsZero());
+}
+
+// Test function for GELU
+BOOST_AUTO_TEST_CASE(test_gelu
+                     , *disabled()
+                     )
+{
+    BOOST_TEST(gelu(0).IsZero());
+    // FIXME: compilability
+    // BOOST_TEST(std::abs(gelu(1) - 0.841344) < (constants::one ^ -6));
+    // BOOST_TEST(std::abs(gelu(-1) - (-0.158655)) < (constants::one ^ -6));
+    BOOST_TEST(gelu(10) == 10);
+    BOOST_TEST(gelu(-10).IsZero());
+}
+
+BOOST_AUTO_TEST_CASE(test_activation_empty) {
+}
\ No newline at end of file