diff --git a/python/sglang/srt/mem_cache/hiradix_cache.py b/python/sglang/srt/mem_cache/hiradix_cache.py
index d2010a531..24b2056e0 100644
--- a/python/sglang/srt/mem_cache/hiradix_cache.py
+++ b/python/sglang/srt/mem_cache/hiradix_cache.py
@@ -305,7 +305,7 @@ class HiRadixCache(RadixCache):
         if value:
             value = torch.cat(value)
         else:
-            value = torch.tensor([], dtype=torch.int32)
+            value = torch.tensor([], dtype=torch.int64)
 
         last_node_global = last_node
         while last_node.evicted:
diff --git a/python/sglang/srt/mem_cache/memory_pool.py b/python/sglang/srt/mem_cache/memory_pool.py
index bdc3ae844..28689268c 100644
--- a/python/sglang/srt/mem_cache/memory_pool.py
+++ b/python/sglang/srt/mem_cache/memory_pool.py
@@ -622,11 +622,10 @@ class HostKVCache(abc.ABC):
         self.mem_state = torch.zeros(
             (self.size,), dtype=torch.uint8, device=self.device
         )
-        self.free_slots = torch.arange(self.size, dtype=torch.int32)
-        self.can_use_mem_size = self.size
 
         # A lock for synchronized operations on memory allocation and state transitions.
         self.lock = threading.RLock()
+        self.clear()
 
     @abc.abstractmethod
     def get_size_per_token(self):
@@ -656,7 +655,7 @@ class HostKVCache(abc.ABC):
     def clear(self):
         self.mem_state.fill_(0)
         self.can_use_mem_size = self.size
-        self.free_slots = torch.arange(self.size, dtype=torch.int32)
+        self.free_slots = torch.arange(self.size, dtype=torch.int64)
 
     @synchronized
     def get_state(self, indices: torch.Tensor) -> MemoryStateInt:
diff --git a/python/sglang/srt/mem_cache/radix_cache.py b/python/sglang/srt/mem_cache/radix_cache.py
index 58ee432b9..dd608c154 100644
--- a/python/sglang/srt/mem_cache/radix_cache.py
+++ b/python/sglang/srt/mem_cache/radix_cache.py
@@ -140,7 +140,7 @@ class RadixCache(BasePrefixCache):
             return (
                 torch.empty(
                     (0,),
-                    dtype=torch.int32,
+                    dtype=torch.int64,
                     device=self.device,
                 ),
                 self.root_node,
@@ -154,7 +154,7 @@ class RadixCache(BasePrefixCache):
         if value:
             value = torch.cat(value)
         else:
-            value = torch.empty((0,), dtype=torch.int32, device=self.device)
+            value = torch.empty((0,), dtype=torch.int64, device=self.device)
         return value, last_node
 
     def insert(self, key: List, value=None):