diff --git a/tianshou/policy/modelfree/dqn.py b/tianshou/policy/modelfree/dqn.py
index b337e9c..58df054 100644
--- a/tianshou/policy/modelfree/dqn.py
+++ b/tianshou/policy/modelfree/dqn.py
@@ -150,9 +150,10 @@ class DQNPolicy(BasePolicy):
         # add eps to act
         if eps is None:
             eps = self.eps
-        for i in range(len(q)):
-            if np.random.rand() < eps:
-                act[i] = np.random.randint(q.shape[1])
+        if not np.isclose(eps, 0):
+            for i in range(len(q)):
+                if np.random.rand() < eps:
+                    act[i] = np.random.randint(q.shape[1])
         return Batch(logits=q, act=act, state=h)
 
     def learn(self, batch: Batch, **kwargs) -> Dict[str, float]: