diff --git a/creds/rust-toolchain b/creds/rust-toolchain
index 2bf5ad04..e88baf10 100644
--- a/creds/rust-toolchain
+++ b/creds/rust-toolchain
@@ -1 +1,2 @@
-stable
+[toolchain]
+channel = "1.88.0"
diff --git a/forks/halo2curves/src/lib.rs b/forks/halo2curves/src/lib.rs
index 2e21ce02..6af17c48 100644
--- a/forks/halo2curves/src/lib.rs
+++ b/forks/halo2curves/src/lib.rs
@@ -1,3 +1,4 @@
+#![allow(dead_code)]
 mod arithmetic;
 mod curve;
 pub mod ff_ext;
diff --git a/sample/client_helper/rust-toolchain b/sample/client_helper/rust-toolchain
new file mode 100644
index 00000000..e88baf10
--- /dev/null
+++ b/sample/client_helper/rust-toolchain
@@ -0,0 +1,2 @@
+[toolchain]
+channel = "1.88.0"