diff --git a/.github/workflows/ci.shellcode.yml b/.github/workflows/ci.shellcode.yml
index e12477fe..8e4d6ea0 100644
--- a/.github/workflows/ci.shellcode.yml
+++ b/.github/workflows/ci.shellcode.yml
@@ -3,7 +3,8 @@ name: ci·shellcode
 on:
   pull_request:
     paths:
-      - src/modes/shellcode.ts
+      - src/modes/shellcode.*
+      - src/prefab/construct-env.*
       - .github/workflows/ci.shellcode.yml
 
   workflow_call:
diff --git a/src/prefab/construct-env.ts b/src/prefab/construct-env.ts
index 0cf22dcd..45c63650 100644
--- a/src/prefab/construct-env.ts
+++ b/src/prefab/construct-env.ts
@@ -26,7 +26,8 @@ export default async function(pkgenv: { installations: Installation[] }) {
     rv[key] = rv[key].replaceAll(new RegExp(`\\$${key}\\b`, 'g'), `\${${key}}`)
     // don’t end with a trailing `:` since that is sometimes interpreted as CWD and can break things
     // instead of `foo:${PATH}` we end up with `foo${PATH:+:PATH}` which is not POSIX but works
-    // with all realy shells to avoid the trailing `:`
+    // with all the shells that we support shellcode for and avoids a trailing `:`
+    // NOTE this may not work with FISH though.
     rv[key] = rv[key].replaceAll(new RegExp(`:+\\$\{${key}}$`, 'g'), `\${${key}:+:$${key}}`)
   }