diff --git a/test/test_temperatur.c b/test/test_temperatur.c
index 04485a8..7f8eeb3 100644
--- a/test/test_temperatur.c
+++ b/test/test_temperatur.c
@@ -18,6 +18,12 @@ float result = CzuF(25);
 float expected = 77;
 TEST_ASSERT_EQUAL(expected, result);
 }
+void test_temperaturRechner_CzuFnegativ(void)
+{
+float result = CzuF(-5);
+float expected = 23;
+TEST_ASSERT_EQUAL(expected, result);
+}
 
 void test_temperaturRechner_CzuK(void)
 {