diff --git a/cryptol-remote-api/python/CHANGELOG.md b/cryptol-remote-api/python/CHANGELOG.md
index 3dc86dffc..52f74ea3f 100644
--- a/cryptol-remote-api/python/CHANGELOG.md
+++ b/cryptol-remote-api/python/CHANGELOG.md
@@ -1,6 +1,9 @@
 # Revision history for `cryptol` Python package
 
-## next -- TBA
+## 3.2.1 -- 2024-08-18
+
+* Require building with `argo-client-0.0.13` or later. `argo-client-0.0.13` uses
+  blocking IO, which should reduce CPU load when receiving replies.
 
 ## 3.2.0 -- 2024-08-20
 
diff --git a/cryptol-remote-api/python/poetry.lock b/cryptol-remote-api/python/poetry.lock
index c2ad99b9a..7a9a9e339 100644
--- a/cryptol-remote-api/python/poetry.lock
+++ b/cryptol-remote-api/python/poetry.lock
@@ -2,13 +2,13 @@
 
 [[package]]
 name = "argo-client"
-version = "0.0.12"
+version = "0.0.13"
 description = "A JSON RPC client library."
 optional = false
 python-versions = "<4,>=3.8.0"
 files = [
-    {file = "argo_client-0.0.12-py3-none-any.whl", hash = "sha256:6986b79f03d6592cdcc87cb228a0829cedf12852134c3af9083a322fa28bdc4a"},
-    {file = "argo_client-0.0.12.tar.gz", hash = "sha256:97f5b2db3caa4598c5cdcb1e9c80b5d330bdc5ecae08e36198e4dab217af4b97"},
+    {file = "argo_client-0.0.13-py3-none-any.whl", hash = "sha256:dd7fdab6b0aecc04c10cfb0ce2989289ebd8f9ae03d9bded16fb6ff8d5c400cb"},
+    {file = "argo_client-0.0.13.tar.gz", hash = "sha256:2cbacdfaa801a89889536145ea46c63d42fa34ae0354bb4f05c39f46074939b4"},
 ]
 
 [package.dependencies]
@@ -282,4 +282,4 @@ zstd = ["zstandard (>=0.18.0)"]
 [metadata]
 lock-version = "2.0"
 python-versions = ">=3.8.0,<4"
-content-hash = "79eb7e6a2b0a2e765d5b699665389a58e1919bf4f7afe811cfdb60271b2e94d4"
+content-hash = "483c7256fb805aeed18a9471d6beedd295b41aebf2b7dc3421f4c950a428cbd8"
diff --git a/cryptol-remote-api/python/pyproject.toml b/cryptol-remote-api/python/pyproject.toml
index da577c11d..e2c6358c4 100644
--- a/cryptol-remote-api/python/pyproject.toml
+++ b/cryptol-remote-api/python/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "cryptol"
-version = "3.2.0.99"
+version = "3.2.1.99"
 readme = "README.md"
 keywords = ["cryptography", "verification"]
 description = "Cryptol client for the Cryptol RPC server"
@@ -15,7 +15,7 @@ include = [
 [tool.poetry.dependencies]
 python = ">=3.8.0,<4"
 BitVector = "^3.4.9"
-argo-client = "0.0.12"
+argo-client = ">=0.0.13"
 typing-extensions = "^4.1.1"
 
 requests = ">=2.31.0"