diff --git a/tests/test_model.py b/tests/test_model.py
new file mode 100644
index 0000000..e6e8f8c
--- /dev/null
+++ b/tests/test_model.py
@@ -0,0 +1,6 @@
+import tiktoken
+def test_gpt5_encoding():
+    encoding = tiktoken.encoding_for_model("gpt-5")
+    assert encoding.name == "o200k_base"
+    tokens = encoding.encode("hello world")
+    assert tokens == [24912, 2375]  # Verify o200k_base behavior
\ No newline at end of file
diff --git a/tiktoken/model.py b/tiktoken/model.py
index 0f9c011..5c669af 100644
--- a/tiktoken/model.py
+++ b/tiktoken/model.py
@@ -32,6 +32,7 @@
     "o3": "o200k_base",
     "o4-mini": "o200k_base",
     # chat
+    "gpt-5": "o200k_base",
     "gpt-4.1": "o200k_base",
     "gpt-4o": "o200k_base",
     "gpt-4": "cl100k_base",