diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c72a07e3b04e..409686883ae6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -420,8 +420,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: dtolnay/rust-toolchain@nightly
+      - uses: dtolnay/rust-toolchain@master
         with:
+          toolchain: nightly-2024-02-08
           components: "rust-src"
       - name: Cache cargo registry
         uses: Swatinem/rust-cache@v2
@@ -429,20 +430,20 @@ jobs:
           key: sqlite_bundled-cargo-${{ hashFiles('**/Cargo.toml') }}
 
       - name: Test diesel-cli
-        run: cargo +nightly test --manifest-path diesel_cli/Cargo.toml --no-default-features --features "sqlite-bundled"
+        run: cargo +${{steps.toolchain.outputs.name} test --manifest-path diesel_cli/Cargo.toml --no-default-features --features "sqlite-bundled"
 
       - name: Run diesel_tests with ASAN enabled
         env:
           RUSTFLAGS: -Zsanitizer=address
           ASAN_OPTIONS: detect_stack_use_after_return=1
-        run: cargo +nightly -Z build-std test --manifest-path diesel_tests/Cargo.toml --no-default-features --features "sqlite libsqlite3-sys libsqlite3-sys/bundled libsqlite3-sys/with-asan" --target x86_64-unknown-linux-gnu
+        run: cargo +${{steps.toolchain.outputs.name} -Z build-std test --manifest-path diesel_tests/Cargo.toml --no-default-features --features "sqlite libsqlite3-sys libsqlite3-sys/bundled libsqlite3-sys/with-asan" --target x86_64-unknown-linux-gnu
 
       - name: Run diesel tests with ASAN enabled
         env:
           RUSTDOCFLAGS: -Zsanitizer=address
           RUSTFLAGS: -Zsanitizer=address
           ASAN_OPTIONS: detect_stack_use_after_return=1
-        run: cargo +nightly -Z build-std test --manifest-path diesel/Cargo.toml --no-default-features --features "sqlite extras libsqlite3-sys libsqlite3-sys/bundled libsqlite3-sys/with-asan" --target x86_64-unknown-linux-gnu
+        run: cargo +${{steps.toolchain.outputs.name} -Z build-std test --manifest-path diesel/Cargo.toml --no-default-features --features "sqlite extras libsqlite3-sys libsqlite3-sys/bundled libsqlite3-sys/with-asan" --target x86_64-unknown-linux-gnu
 
   minimal_rust_version:
     name: Check Minimal supported rust version (1.70.0)
diff --git a/diesel/src/pg/types/json.rs b/diesel/src/pg/types/json.rs
index 059c86341ae6..9f43addf5e2e 100644
--- a/diesel/src/pg/types/json.rs
+++ b/diesel/src/pg/types/json.rs
@@ -46,9 +46,13 @@ impl ToSql<sql_types::Jsonb, Pg> for serde_json::Value {
     }
 }
 
-#[cfg(tests)]
+#[cfg(test)]
 mod tests {
-    use crate::query_builder::bind_types::ByteWrapper;
+    use crate::deserialize::FromSql;
+    use crate::pg::{Pg, PgValue};
+    use crate::query_builder::bind_collector::ByteWrapper;
+    use crate::serialize::{Output, ToSql};
+    use crate::sql_types;
 
     #[test]
     fn json_to_sql() {
diff --git a/rust-toolchain b/rust-toolchain
index 7c7053aa2388..32a6ce3c719b 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-1.75.0
+1.76.0