diff --git a/src/c/funktionen.c b/src/c/funktionen.c
index 9ac25d1..63a8976 100644
--- a/src/c/funktionen.c
+++ b/src/c/funktionen.c
@@ -79,6 +79,12 @@ int x_wins_20_21_22(char board[][3]) {
     }    
 }
 
+int x_wins_00_11_22(char board[][3]) {
+    if (board[0][0] == 'X' && board[1][1] == 'X' && board[2][2] == 'X') {
+        return 1;
+    }    
+}
+
 int string_character_counter(char string[]) {
     int stringLength = 0;
 
diff --git a/src/test/test_funktionen.c b/src/test/test_funktionen.c
index 640ac1b..288590c 100644
--- a/src/test/test_funktionen.c
+++ b/src/test/test_funktionen.c
@@ -166,6 +166,21 @@ void test_x_wins_onIndex_20_21_22(void)
     TEST_ASSERT_EQUAL_INT(expected, actual);
 }
 
+void test_x_wins_onIndex_00_11_22(void)
+{
+    /* arrange */
+    int actual;
+    int expected = 1;
+    
+    char board[][3] = {{'X',' ',' '}, {' ','X',' '}, {' ',' ','X'}};
+
+    /* act */
+    actual = x_wins_00_11_22(board);
+
+    /* assert */
+    TEST_ASSERT_EQUAL_INT(expected, actual);
+}
+
 void test_stringLaenge_von_Kokosnuss(void)
 {
     /* arrange */