diff --git a/.clang-tidy b/.clang-tidy
index 5378d1d..1a65418 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -15,6 +15,7 @@ Checks: >
   -readability-identifier-length,
   -readability-implicit-bool-conversion,
   -readability-magic-numbers,
+  -readability-math-missing-parentheses,
   -readability-named-parameter,
   -readability-static-definition-in-anonymous-namespace,
   -readability-uppercase-literal-suffix,
@@ -30,12 +31,14 @@ Checks: >
   -bugprone-narrowing-conversions,
   modernize-*,
   -modernize-avoid-c-arrays,
+  -modernize-concat-nested-namespaces,
   -modernize-make-unique,
   -modernize-use-auto,
+  -modernize-use-designated-initializers,
   -modernize-use-nodiscard,
+  -modernize-use-std-format,
   -modernize-use-std-print,
   -modernize-use-trailing-return-type,
-  -modernize-concat-nested-namespaces,
   misc-*,
   -misc-no-recursion,
   -misc-unused-parameters,
diff --git a/shell.nix b/shell.nix
index a7204ee..b6022a4 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,23 +1,30 @@
 { pkgs ? import <nixpkgs> {} }:
 let
   bazel = pkgs.bazel_7;
-  clangTools = pkgs.clang-tools_18;
+
+  # There is too much volatility between even micro-versions of
+  # newer clang-format. Use slightly older version for now.
+  clang_for_formatting = pkgs.llvmPackages_18.clang-tools;
+
+  # clang tidy: use latest.
+  clang_for_tidy = pkgs.llvmPackages_18.clang-tools;
 in
 pkgs.mkShell {
-  name = "prjxtream";
+  name = "fpga-assembler";
   packages = with pkgs; [
     git
     bazel
     jdk
     bash
-    bant
     gdb
 
     # For clang-tidy and clang-format.
-    clangTools
+    clang_for_formatting
+    clang_for_tidy
 
     # For buildifier, buildozer.
     bazel-buildtools
+    bant
 
     # Profiling and sanitizers.
     linuxPackages_latest.perf
@@ -26,10 +33,6 @@ pkgs.mkShell {
     valgrind
   ];
 
-  # Expose as env variables the path to clang tools.
-  CLANG_TIDY = "${clangTools}/bin/clang-tidy";
-  CLANG_FORMAT = "${clangTools}/bin/clang-format";
-
-  # Override .bazelversion. We only care to have bazel 7.
-  USE_BAZEL_VERSION = "${bazel.version}";
+  CLANG_TIDY="${clang_for_tidy}/bin/clang-tidy";
+  CLANG_FORMAT="${clang_for_formatting}/bin/clang-format";
 }