diff --git a/al_bool_matrix.hpp b/al_bool_matrix.hpp
index f7c4596..94fcbba 100644
--- a/al_bool_matrix.hpp
+++ b/al_bool_matrix.hpp
@@ -57,12 +57,26 @@ class BoolSquareMatrix {
             return (_values >> index(row, col)) % 2;
         }
         STORAGE get_determinant() {
-            if ( SIZE == 2 ) {
+            if constexpr ( SIZE == 2 ) {
                 return at(0,0) * at(1,1) - at(0,1) * at(1,0);
-            } else if ( SIZE == 3 ) {
-                return at(0,0) * at(1,1) * at(2,2) + at(0,1) * at(1,2) * at(2,0)
-                    + at(0,2) * at(1,0) * at(2,1) - at(0,2) * at(1,1) * at(2,0)
-                    - at(0,1) * at(1,0) * at(2,2) - at(0,0) * at(1,2) * at(2,1);
+            } else if constexpr ( SIZE == 4 or SIZE == 3 ) {
+                int cur_modifier = 1;
+                STORAGE res = 0;
+                for (STORAGE remove_ind = 0; remove_ind < SIZE; ++remove_ind) {
+                    STORAGE tmp_vector_value = 0;
+                    for (STORAGE i = 1; i < SIZE; ++i) {
+                        for (STORAGE j = 0; j < SIZE; ++j) {
+                            if ( j == remove_ind )
+                                continue;
+                            tmp_vector_value *= 2;
+                            tmp_vector_value += at(i, j);
+                        }
+                    }
+                    BoolSquareMatrix<STORAGE, SIZE - 1> tmp_matix(tmp_vector_value);
+                    res += cur_modifier * tmp_matix.get_determinant() * at(0, remove_ind);
+                    cur_modifier *= -1;
+                }
+                return res;
             }
         }
 
diff --git a/main.cpp b/main.cpp
index b6355ed..5e270c9 100644
--- a/main.cpp
+++ b/main.cpp
@@ -59,6 +59,16 @@ void test_function() {
     assert(minus_i_matrix.string("") == "001010100");
     assert(minus_i_matrix.get_determinant() == uint16_t(-1));
 
+    BoolSquareMatrix<uint16_t, 4> ones_matrix_4(0b1111111111111111),
+        i_matrix_4(0b1000010000100001),
+        minus_i_matrix_4(0b0001001001001000);
+    assert(ones_matrix_4.string("") == "1111111111111111");
+    assert(ones_matrix_4.get_determinant() == 0);
+    assert(i_matrix_4.string("") == "1000010000100001");
+    assert(i_matrix_4.get_determinant() == 1);
+    assert(minus_i_matrix_4.string("") == "0001001001001000");
+    assert(minus_i_matrix_4.get_determinant() == 1);
+
     cout << "self-test passed" << endl;
 }