diff --git a/src/temperatur.h b/src/temperatur.h
index 9cb94b5..226e114 100644
--- a/src/temperatur.h
+++ b/src/temperatur.h
@@ -3,5 +3,6 @@
 
 float CzuF(float tempC);
 float CzuK(float tempC);
+float FzuC(float tempF);
 
 #endif //TEMPERATUR_H
diff --git a/test/test_temperatur.c b/test/test_temperatur.c
index 584ce47..9751fc2 100644
--- a/test/test_temperatur.c
+++ b/test/test_temperatur.c
@@ -26,4 +26,11 @@ float expected = 298.15;
 TEST_ASSERT_EQUAL(expected, result);
 }
 
+
+void test_temperaturRechner_FzuC(void)
+{
+float result = FzuC(77);
+float expected = 25;
+TEST_ASSERT_EQUAL(expected, result);
+}
 #endif