diff --git a/src/test/test_funktionen.c b/src/test/test_funktionen.c
index 7dc2b47..09ca587 100644
--- a/src/test/test_funktionen.c
+++ b/src/test/test_funktionen.c
@@ -76,4 +76,19 @@ void test_2_toThePowerOf_7(void)
     TEST_ASSERT_EQUAL_INT(expected, actual);
 }
 
+void test_x_wins_onIndex_00_10_20(void)
+{
+    /* arrange */
+    int actual;
+    int expected = 1;
+    
+    char board[][3] = {{'X',' ',' '}, {'X',' ',' '}, {'X',' ',' '}};
+
+    /* act */
+    actual = x_wins_00_10_20(board);
+
+    /* assert */
+    TEST_ASSERT_EQUAL_INT(expected, actual);
+}
+
 #endif
\ No newline at end of file