diff --git a/source/Age/Age.cpp b/source/Age/Age.cpp
index 81415e9..05613a4 100644
--- a/source/Age/Age.cpp
+++ b/source/Age/Age.cpp
@@ -4,8 +4,8 @@
 #include <sstream>
 
 Age::Age(unsigned int years, unsigned int months)
-	: m_years(years)
-	, m_months(months)
+    : m_years(years)
+    , m_months(months)
 {
 }
 
@@ -37,7 +37,7 @@ Age::Age(const QDate &birth, const QDate &reference)
 	m_years = years;
 	m_months = months;
 }
-	
+
 bool Age::operator<(const Age &cmp) const
 {
 	if (m_years == cmp.m_years)
@@ -47,7 +47,7 @@ bool Age::operator<(const Age &cmp) const
 
 	return m_years < cmp.m_years;
 }
-	
+
 unsigned int Age::years() const
 {
 	return m_years;
@@ -57,7 +57,7 @@ unsigned int Age::months() const
 {
 	return m_months;
 }
- 
+
 std::string Age::toString() const
 {
 	std::ostringstream result;
diff --git a/test/Age.cpp b/test/Age.cpp
index 34b3788..22b0fbb 100644
--- a/test/Age.cpp
+++ b/test/Age.cpp
@@ -18,7 +18,7 @@ TEST_CASE("year/month initialization")
 {
 	for (unsigned int year = 0; year <= 100; ++year)
 	{
-		for (unsigned int month = 1; month <= 12; ++month)
+		for (unsigned int month = 0; month < 12; ++month)
 		{
 			Age age(year, month);
 
@@ -27,3 +27,14 @@ TEST_CASE("year/month initialization")
 		}
 	}
 }
+
+TEST_CASE("age by reference")
+{
+	QDate birth(1970, 1, 1);
+	QDate reference(1980, 1, 1);
+
+	Age age(birth, reference);
+
+	REQUIRE(age.years() == 10);
+	REQUIRE(age.months() == 0);
+}