diff --git a/llama_cpp/llama.py b/llama_cpp/llama.py
index 5c66bcf..538781d 100644
--- a/llama_cpp/llama.py
+++ b/llama_cpp/llama.py
@@ -194,16 +194,16 @@ class Llama:
         self.model_params.use_mmap = use_mmap if lora_path is None else False
         self.model_params.use_mlock = use_mlock
 
+        # kv_overrides is the original python dict
         self.kv_overrides = kv_overrides
         if kv_overrides is not None:
-            n_overrides = len(kv_overrides)
-            self._kv_overrides_array = llama_cpp.llama_model_kv_override * (n_overrides + 1)
-            self._kv_overrides_array_keys = []
 
-            for k, v in kv_overrides.items():
-                key_buf = ctypes.create_string_buffer(k.encode("utf-8"))
-                self._kv_overrides_array_keys.append(key_buf)
-                self._kv_overrides_array[i].key = key_buf
+            # _kv_overrides_array is a ctypes.Array of llama_model_kv_override Structs
+            kvo_array_len = len(kv_overrides) + 1   # for sentinel element
+            self._kv_overrides_array = (llama_cpp.llama_model_kv_override * kvo_array_len)()
+
+            for i, (k, v) in enumerate(kv_overrides.items()):
+                self._kv_overrides_array[i].key = k.encode('utf-8');
                 if isinstance(v, int):
                     self._kv_overrides_array[i].tag = llama_cpp.LLAMA_KV_OVERRIDE_INT
                     self._kv_overrides_array[i].value.int_value = v
@@ -216,10 +216,7 @@ class Llama:
                 else:
                     raise ValueError(f"Unknown value type for {k}: {v}")
 
-            self._kv_overrides_array_sentinel_key = b'\0'
-
-            # null array sentinel
-            self._kv_overrides_array[n_overrides].key = self._kv_overrides_array_sentinel_key
+            self._kv_overrides_array[-1].key = b'\0'  # ensure sentinel element is zeroed
             self.model_params.kv_overrides = self._kv_overrides_array
 
         self.n_batch = min(n_ctx, n_batch)  # ???