diff --git a/CHANGELOG.md b/CHANGELOG.md
index f533c28..6b98e49 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [1.1.39] - 2025-11-21
+
+## Added
+
+- Add support for new model: `gpt-5.1`
+
 ## [1.1.38] - 2025-11-13
 
 ## Added
@@ -386,7 +392,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Release of the Cleanlab TLM Python client.
 
-[Unreleased]: https://github.com/cleanlab/cleanlab-tlm/compare/v1.1.38...HEAD
+[Unreleased]: https://github.com/cleanlab/cleanlab-tlm/compare/v1.1.39...HEAD
+[1.1.39]: https://github.com/cleanlab/cleanlab-tlm/compare/v1.1.38...v1.1.39
 [1.1.38]: https://github.com/cleanlab/cleanlab-tlm/compare/v1.1.37...v1.1.38
 [1.1.37]: https://github.com/cleanlab/cleanlab-tlm/compare/v1.1.36...v1.1.37
 [1.1.36]: https://github.com/cleanlab/cleanlab-tlm/compare/v1.1.35...v1.1.36
diff --git a/src/cleanlab_tlm/__about__.py b/src/cleanlab_tlm/__about__.py
index ff8b807..5167cc3 100644
--- a/src/cleanlab_tlm/__about__.py
+++ b/src/cleanlab_tlm/__about__.py
@@ -1,2 +1,2 @@
 # SPDX-License-Identifier: MIT
-__version__ = "1.1.38"
+__version__ = "1.1.39"
diff --git a/src/cleanlab_tlm/internal/constants.py b/src/cleanlab_tlm/internal/constants.py
index 9c751f0..5d08f76 100644
--- a/src/cleanlab_tlm/internal/constants.py
+++ b/src/cleanlab_tlm/internal/constants.py
@@ -20,6 +20,7 @@
     "gpt-5",
     "gpt-5-mini",
     "gpt-5-nano",
+    "gpt-5.1",
     "o1-preview",
     "o1",
     "o1-mini",
diff --git a/src/cleanlab_tlm/tlm.py b/src/cleanlab_tlm/tlm.py
index b0ef7b0..e564c5b 100644
--- a/src/cleanlab_tlm/tlm.py
+++ b/src/cleanlab_tlm/tlm.py
@@ -771,12 +771,12 @@ class TLMOptions(TypedDict):
     You can set custom values for these arguments regardless of the quality preset specified.
 
     Args:
-        model ({"gpt-5", "gpt-5-mini", "gpt-5-nano", "gpt-4.1", "gpt-4.1-mini", "gpt-4.1-nano", "o4-mini", "o3", "gpt-4.5-preview", "gpt-4o-mini", "gpt-4o", \
+        model ({"gpt-5.1", "gpt-5", "gpt-5-mini", "gpt-5-nano", "gpt-4.1", "gpt-4.1-mini", "gpt-4.1-nano", "o4-mini", "o3", "gpt-4.5-preview", "gpt-4o-mini", "gpt-4o", \
          "o3-mini", "o1", "o1-mini", "gpt-4", "gpt-3.5-turbo-16k", "claude-opus-4-0", "claude-sonnet-4-0", "claude-3.7-sonnet",  \
          "claude-3.5-sonnet-v2", "claude-3.5-sonnet", "claude-3.5-haiku", "claude-3-haiku", "nova-micro", "nova-lite", "nova-pro"}, default = "gpt-4.1-mini"): \
         Underlying base LLM to use (better models yield better results, faster models yield faster results).
         - Models still in beta: "o3", "o1", "o4-mini", "o3-mini", "o1-mini", "gpt-4.5-preview", "claude-opus-4-0", "claude-sonnet-4-0", "claude-3.7-sonnet", "claude-3.5-haiku".
-        - Recommended models for accuracy: "gpt-5", "gpt-4.1", "o4-mini", "o3", "claude-opus-4-0", "claude-sonnet-4-0".
+        - Recommended models for accuracy: "gpt-5.1", "gpt-4.1", "o3", "claude-opus-4-0", "claude-sonnet-4-0".
         - Recommended models for low latency/costs: "gpt-4.1-nano", "nova-micro".
 
         log (list[str], default = []): optionally specify additional logs or metadata that TLM should return.
diff --git a/tests/constants.py b/tests/constants.py
index 61559f0..cf883e5 100644
--- a/tests/constants.py
+++ b/tests/constants.py
@@ -59,6 +59,7 @@
     "o3-mini",
     "o4-mini",
     "gpt-4.5-preview",
+    "gpt-5.1",  # supports perplexity score in some configs, should update at a later date
     "gpt-5",
     "gpt-5-mini",
     "gpt-5-nano",