diff --git a/src/test/cunit.c b/src/test/cunit.c
index b2913a4..5a8ef43 100644
--- a/src/test/cunit.c
+++ b/src/test/cunit.c
@@ -99,7 +99,11 @@ int main(void)
 		(NULL == CU_add_test(pSuite, "test1 finding center ob obj",
 							 test_find_center1)) ||
 		(NULL == CU_add_test(pSuite, "test2 finding center ob obj",
-							 test_find_center2))
+							 test_find_center2)) ||
+		(NULL == CU_add_test(pSuite, "test1 getting normalized scale factor",
+							 test_get_normalized_scale_factor1)) ||
+		(NULL == CU_add_test(pSuite, "test2 getting normalized scale factor",
+							 test_get_normalized_scale_factor2))
 		) {
 
 		CU_cleanup_registry();
diff --git a/src/test/cunit.h b/src/test/cunit.h
index 9e7b9c8..8ecbf53 100644
--- a/src/test/cunit.h
+++ b/src/test/cunit.h
@@ -38,3 +38,6 @@ void test_parse_obj4(void);
 
 void test_find_center1(void);
 void test_find_center2(void);
+
+void test_get_normalized_scale_factor1(void);
+void test_get_normalized_scale_factor2(void);
diff --git a/src/test/cunit_half_edge.c b/src/test/cunit_half_edge.c
index 42eae54..dc1590b 100644
--- a/src/test/cunit_half_edge.c
+++ b/src/test/cunit_half_edge.c
@@ -462,3 +462,36 @@ void test_find_center2(void)
 
 	CU_ASSERT_PTR_NULL(newvert);
 }
+
+void test_get_normalized_scale_factor1(void)
+{
+	char const * const string = ""
+		"v 9.0 10.0 11.0\n"
+		"v 11.0 10.0 11.0\n"
+		"v 9.0 11.0 11.0\n"
+		"v 11.0 11.0 11.0\n"
+		"v 9.0 11.0 9.0\n"
+		"v 11.0 11.0 9.0\n"
+		"v 9.0 10.0 9.0\n"
+		"v 11.0 10.0 9.0\n"
+		"f 1 2 4 3\n"
+		"f 3 4 6 5\n"
+		"f 5 6 8 7\n"
+		"f 7 8 2 1\n"
+		"f 2 8 6 4\n"
+		"f 7 1 3 5\n";
+
+	HE_obj *obj = parse_obj(string);
+	HE_vert *newvert = find_center(obj);
+	float factor = get_normalized_scale_factor(obj);
+
+	CU_ASSERT_PTR_NOT_NULL(obj);
+	CU_ASSERT_EQUAL(factor, 0.2f);
+}
+
+void test_get_normalized_scale_factor2(void)
+{
+	float factor = get_normalized_scale_factor(NULL);
+
+	CU_ASSERT_EQUAL(factor, -1);
+}