diff --git a/halo2-base/src/gates/flex_gate/mod.rs b/halo2-base/src/gates/flex_gate/mod.rs
index 5dea4228..b025c23c 100644
--- a/halo2-base/src/gates/flex_gate/mod.rs
+++ b/halo2-base/src/gates/flex_gate/mod.rs
@@ -137,7 +137,7 @@ impl<F: ScalarField> FlexGateConfig<F> {
         Self {
             basic_gates,
             constants,
-            /// Warning: this needs to be updated if you create more advice columns after this `FlexGateConfig` is created
+            // Warning: this needs to be updated if you create more advice columns after this `FlexGateConfig` is created
             max_rows: (1 << params.k) - meta.minimum_rows(),
         }
     }
diff --git a/rust-toolchain b/rust-toolchain
index ee2d639b..36e57ce7 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-nightly-2023-08-12
\ No newline at end of file
+nightly-2024-02-08