diff --git a/src/ageinseconds.h b/src/ageinseconds.h
index 18518cc..5122b87 100644
--- a/src/ageinseconds.h
+++ b/src/ageinseconds.h
@@ -1,5 +1,6 @@
 #ifndef AGEINSECONDS_H
 #define AGEINSECONDS_H
 
+int sekunden(int jahre);
 
 #endif // AGEINSECONDS_H
diff --git a/test/test_ageinseconds.c b/test/test_ageinseconds.c
index 30a28d3..d1acd58 100644
--- a/test/test_ageinseconds.c
+++ b/test/test_ageinseconds.c
@@ -12,4 +12,11 @@ void tearDown(void)
 {
 }
 
+// test sekunden
+void test_ageinseconds_45_in_sekunden(void)
+{
+    float result = sekunden(45);
+    TEST_ASSERT_EQUAL(1419120000, result);
+}
+
 #endif // TEST