diff --git a/src/temperatur.h b/src/temperatur.h
index d4f13bf..6063d96 100644
--- a/src/temperatur.h
+++ b/src/temperatur.h
@@ -10,4 +10,5 @@ float FzuK(float tempF);
 float KzuC(float tempK);
 float KzuF(float tempK);
 
+const char* getFirstUnit(int input);
 #endif //TEMPERATUR_H
diff --git a/test/test_temperatur.c b/test/test_temperatur.c
index e22c8e1..c1a14fb 100644
--- a/test/test_temperatur.c
+++ b/test/test_temperatur.c
@@ -53,4 +53,10 @@ float expected = 77;
 TEST_ASSERT_EQUAL(expected, result);
 }
 
+void test_returnUnit_first(void)
+{
+const char *result = getFirstUnit(1);
+char expected[] = "Celsius";
+TEST_ASSERT_EQUAL_STRING(expected, result);
+}
 #endif