diff --git a/src/test/c/test_calculator.c b/src/test/c/test_calculator.c
index ba35300..2b0e3e3 100644
--- a/src/test/c/test_calculator.c
+++ b/src/test/c/test_calculator.c
@@ -209,5 +209,14 @@ void test_DecToBin(void) {
     // Assert
     TEST_ASSERT_EQUAL_INT64(100, result);
 }
+void test_BinToDec(void) {
+    // Arrange
+    long long int result;
+
+    // Act
+    result = DecToBin(100);
 
+    // Assert
+    TEST_ASSERT_EQUAL_INT64(8, result);
+}