diff --git a/test/test_tictactoe.c b/test/test_tictactoe.c
index c98770d..0f76b25 100644
--- a/test/test_tictactoe.c
+++ b/test/test_tictactoe.c
@@ -33,4 +33,17 @@ void test_if_identical(void){
     /* assert */
     TEST_ASSERT_EQUAL_CHAR(a, result);
 }
+
+void test_checkLine_horizontalerGewinner(void) {
+    /* arrange */
+    char result;
+    char a = 'X', b = 'X', c = 'X';
+
+    /* assert */
+    result = checkLine(a, b, c);
+
+    /* überprüfen */
+    TEST_ASSERT_EQUAL_CHAR('X', result);
+}
+}
 #endif // TEST