diff --git a/ttt/game.py b/ttt/game.py
index 2f0e302..49c4e9b 100644
--- a/ttt/game.py
+++ b/ttt/game.py
@@ -58,4 +58,21 @@ class TTTGame:
 
     def check_winner(self, state, symbol):
         "Checks whether the player with `symbol` has won the game."
+        b=state['board']
+        if b[0]==symbol and b[3]==symbol and b[6]==symbol:
+            return True
+        if b[1]==symbol and b[4]==symbol and b[7]==symbol:
+            return True
+        if b[2]==symbol and b[5]==symbol and b[8]==symbol:
+            return True
+        if b[0]==symbol and b[1]==symbol and b[2]==symbol:
+            return True
+        if b[3]==symbol and b[4]==symbol and b[5]==symbol:
+            return True
+        if b[6]==symbol and b[7]==symbol and b[8]==symbol:
+            return True
+        if b[0]==symbol and b[4]==symbol and b[8]==symbol:
+            return True
+        if b[2]==symbol and b[4]==symbol and b[6]==symbol:
+            return True
         return False