diff --git a/docs/trajectories/typescript-bun-migration/RESUME.md b/docs/trajectories/typescript-bun-migration/RESUME.md
index e07b9bd921..6947ff7daa 100644
--- a/docs/trajectories/typescript-bun-migration/RESUME.md
+++ b/docs/trajectories/typescript-bun-migration/RESUME.md
@@ -6,7 +6,7 @@
 **Next concrete action**: Maintain the bash-retirement inventory guard and treat
 any newly tracked non-Lean shell-family file outside the allowlist as drift. Do
 not revive the old Cluster G/H/I or budget-cluster port queues.
-**Last updated**: 2026-05-27T17:48Z
+**Last updated**: 2026-05-28T12:35Z
 
 ## Why this trajectory exists
 
@@ -52,11 +52,12 @@ bun run hygiene:check-bash-retirement-inventory
 The expected retained surface is the explicit repo-wide allowlist: setup and
 bootstrap scripts, host-service wrappers, NixOS installer scripts,
 dev-cluster wrappers, launchd-bootstrap, and the Kiro loop wrapper. Any new
-non-Lean shell-family file (`.sh`, `.bash`, `.zsh`, `.ksh`, or `.command`)
-outside the allowlist is bash-retirement drift. Executable dotted-name files
-with shell-family shebangs are also entrypoints and are classified as drift;
-non-executable dotted documentation fixtures with shell-looking first lines stay
-outside the retained-shell inventory.
+non-Lean shell-family file (`.sh`, `.bash`, `.zsh`, `.ksh`, or `.command`,
+including uppercase extension variants) outside the allowlist is
+bash-retirement drift. Executable dotted-name files with shell-family shebangs
+are also entrypoints and are classified as drift; non-executable dotted
+documentation fixtures with shell-looking first lines stay outside the
+retained-shell inventory.
 
 ### Bucket A — Should stay Shell (21 files)
 
diff --git a/tools/hygiene/check-bash-retirement-inventory.test.ts b/tools/hygiene/check-bash-retirement-inventory.test.ts
index bd07ba342b..837dc34d7c 100644
--- a/tools/hygiene/check-bash-retirement-inventory.test.ts
+++ b/tools/hygiene/check-bash-retirement-inventory.test.ts
@@ -196,10 +196,15 @@ describe("buildInventoryReport", () => {
       mkdirSync(join(repo, "scripts"), { recursive: true });
       mkdirSync(join(repo, "tools", "lean4"), { recursive: true });
       writeFileSync(join(repo, "scripts", "a.sh"), "#!/usr/bin/env bash\n");
+      writeFileSync(join(repo, "scripts", "a-uppercase.SH"), "echo uppercase extension drift\n");
       writeFileSync(join(repo, "scripts", "b.bash"), "#!/usr/bin/env bash\n");
+      writeFileSync(join(repo, "scripts", "b-uppercase.BASH"), "echo uppercase extension drift\n");
       writeFileSync(join(repo, "scripts", "c.zsh"), "#!/usr/bin/env zsh\n");
+      writeFileSync(join(repo, "scripts", "c-uppercase.ZSH"), "echo uppercase extension drift\n");
       writeFileSync(join(repo, "scripts", "d.ksh"), "#!/usr/bin/env ksh\n");
+      writeFileSync(join(repo, "scripts", "d-uppercase.KSH"), "echo uppercase extension drift\n");
       writeFileSync(join(repo, "scripts", "e.command"), "#!/usr/bin/env bash\n");
+      writeFileSync(join(repo, "scripts", "e-uppercase.COMMAND"), "echo uppercase extension drift\n");
       writeFileSync(join(repo, "scripts", "extensionless-bash"), "#!/usr/bin/env bash\n");
       writeFileSync(join(repo, "scripts", "extensionless-bash-env-s"), "#!/usr/bin/env -S bash -eu\n");
       writeFileSync(join(repo, "scripts", "extensionless-dash"), "#!/bin/dash\n");
@@ -214,11 +219,16 @@ describe("buildInventoryReport", () => {
 
       expect(trackedNonLeanShellFilesFromGit(repo)).toEqual([
         "scripts/a.sh",
+        "scripts/a-uppercase.SH",
         "scripts/b.bash",
+        "scripts/b-uppercase.BASH",
         "scripts/c.zsh",
+        "scripts/c-uppercase.ZSH",
         "scripts/d.ksh",
+        "scripts/d-uppercase.KSH",
         "scripts/dotted-shell-entry.env",
         "scripts/e.command",
+        "scripts/e-uppercase.COMMAND",
         "scripts/extensionless-bash",
         "scripts/extensionless-bash-env-s",
         "scripts/extensionless-dash",
diff --git a/tools/hygiene/check-bash-retirement-inventory.ts b/tools/hygiene/check-bash-retirement-inventory.ts
index c39f50213e..af8d919812 100644
--- a/tools/hygiene/check-bash-retirement-inventory.ts
+++ b/tools/hygiene/check-bash-retirement-inventory.ts
@@ -210,7 +210,8 @@ function parseTrackedGitFile(entry: string): TrackedGitFile | undefined {
 }
 
 function isTrackedShellFamilyFile(repoRoot: string, file: string, executable: boolean): boolean {
-  if (SHELL_FILE_EXTENSIONS.some((extension) => file.endsWith(extension))) return true;
+  const lowerFile = file.toLowerCase();
+  if (SHELL_FILE_EXTENSIONS.some((extension) => lowerFile.endsWith(extension))) return true;
   if (basename(file).includes(".") && !executable) return false;
 
   const firstLine = readFirstLine(join(repoRoot, file));