diff --git a/.github/workflows/python-build-test.yml b/.github/workflows/python-build-test.yml
index 6d4cbeab..27135840 100644
--- a/.github/workflows/python-build-test.yml
+++ b/.github/workflows/python-build-test.yml
@@ -50,7 +50,7 @@ jobs:
       matrix:
         # Rust runtime doesn't support 3.14 yet.
         python-version: ["3.10", "3.11", "3.12", "3.13"]
-        rust-version: [ "1.80.0", "stable" ]
+        rust-version: [ "1.80.0", "1.91.0" ]
       fail-fast: false
     steps:
       - name: Check out from Git
diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index 7a12cc29..f5ada30b 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -31,8 +31,8 @@ itertools = "0.11.0"
 lazy_static = "1.4.0"
 thiserror = "1.0.41"
 bytes = "1.5.0"
-pdl-derive = "0.4.2"
-pdl-runtime = "0.4.2"
+pdl-derive = "0.2.0"
+pdl-runtime = "0.2.0"
 futures = "0.3.28"
 
 # Dev tools