diff --git a/CHANGELOG.md b/CHANGELOG.md
index 83a1a93..3231cad 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -39,6 +39,16 @@ actually cutting it, and this file starts there.
   decrypt, the age key is not demanded either. The moment any template
   gains a `${…}` ref, the refusal returns byte-identical to before.
   `capture` and `destroy` are untouched.
+- **`CAST_AGE_KEY_FILE_<ENV>` is now settable for every environment name**
+  (#102) — `<ENV>` was the name uppercased verbatim, so env `drill-b`
+  advertised `CAST_AGE_KEY_FILE_DRILL-B`: a variable no POSIX shell can
+  export, which walled off the injected-key channel (and its
+  process-substitution trick) for every hyphenated environment. Found live
+  in the 2026-07-19 release drill. Characters outside `[A-Z0-9]` now map to
+  `_` — env `drill-b` reads `CAST_AGE_KEY_FILE_DRILL_B` — and the refusal
+  advertises the mapped name. The standing-key path keeps the exact
+  environment name, so two names that collide on the variable still resolve
+  their own keys on disk.
 
 ### Added
 
diff --git a/README.md b/README.md
index 4f24bc8..06b9359 100644
--- a/README.md
+++ b/README.md
@@ -608,8 +608,12 @@ Coolify's default `production`) in a blueprint that claims to describe the box.
 
 An environment's age identity is resolved in exactly two ways:
 
-1. `$CAST_AGE_KEY_FILE_<ENV>` — injected for this invocation
-2. `~/.config/cast/age-<env>.key` — a standing key on this machine
+1. `$CAST_AGE_KEY_FILE_<ENV>` — injected for this invocation. `<ENV>` is the
+   environment name uppercased, with every character a shell cannot carry in a
+   variable name mapped to `_`: env `drill-b` reads
+   `CAST_AGE_KEY_FILE_DRILL_B`.
+2. `~/.config/cast/age-<env>.key` — a standing key on this machine, under the
+   environment's exact name.
 
 That is the whole mechanism behind attended vs unattended applies: **an
 environment whose key you never leave on disk can only be applied by someone who
diff --git a/src/secrets.ts b/src/secrets.ts
index 6556d6f..ec82f90 100644
--- a/src/secrets.ts
+++ b/src/secrets.ts
@@ -79,15 +79,27 @@ export function encryptSecrets(
 // operator who injects it. Keep the key OUT of the state repo — the state repo
 // holds ciphertext, never the identity that opens it.
 export function keyFileFor(envName: string): string {
-  const injected = process.env[`CAST_AGE_KEY_FILE_${envName.toUpperCase()}`];
+  const injected = process.env[ageKeyVarFor(envName)];
   if (injected) return injected;
   const standing = join(homedir(), ".config", "cast", `age-${envName}.key`);
   if (existsSync(standing)) return standing;
   throw new Error(
-    `no age key for ${envName}: set CAST_AGE_KEY_FILE_${envName.toUpperCase()} (attended apply) or place a standing key at ${standing}`,
+    `no age key for ${envName}: set ${ageKeyVarFor(envName)} (attended apply) or place a standing key at ${standing}`,
   );
 }
 
+// The env var carrying an environment's injected key. Uppercased AND mapped to
+// the character set a shell can actually set: `drill-b`.toUpperCase() is
+// `DRILL-B`, and `CAST_AGE_KEY_FILE_DRILL-B` is a name no POSIX shell can
+// export — the refusal above used to advertise it anyway, an escape hatch that
+// pointed at a wall (#102, found live in the release drill). Every character
+// outside [A-Z0-9] collapses to `_`, so `drill-b` and `drill.b` both read
+// CAST_AGE_KEY_FILE_DRILL_B — a collision that costs nothing, because both
+// names still resolve their OWN standing key (which keeps the exact env name).
+export function ageKeyVarFor(envName: string): string {
+  return `CAST_AGE_KEY_FILE_${envName.toUpperCase().replace(/[^A-Z0-9]/g, "_")}`;
+}
+
 export function secretsFileFor(
   stateDir: string,
   repoShortName: string,
diff --git a/test/secrets.test.ts b/test/secrets.test.ts
index a436552..da908f5 100644
--- a/test/secrets.test.ts
+++ b/test/secrets.test.ts
@@ -107,6 +107,32 @@ describe("keyFileFor", () => {
     expect(keyFileFor("prod")).toBe("/tmp/prod.key");
     Reflect.deleteProperty(process.env, "CAST_AGE_KEY_FILE_PROD");
   });
+  // #102: `drill-b`.toUpperCase() is `DRILL-B`, and a var named
+  // CAST_AGE_KEY_FILE_DRILL-B cannot be set by any POSIX shell — the injected
+  // channel (and its process-substitution trick) was unreachable for every
+  // hyphenated environment name. Non-alphanumerics map to `_`.
+  it("a hyphenated env name maps to a settable var name", () => {
+    process.env.CAST_AGE_KEY_FILE_DRILL_B = "/tmp/drill-b.key";
+    try {
+      expect(keyFileFor("drill-b")).toBe("/tmp/drill-b.key");
+    } finally {
+      Reflect.deleteProperty(process.env, "CAST_AGE_KEY_FILE_DRILL_B");
+    }
+  });
+  it("the refusal advertises the mapped (settable) var, and the exact-name standing path", () => {
+    Reflect.deleteProperty(process.env, "CAST_AGE_KEY_FILE_DRILL_B");
+    // Isolate $HOME: a standing age-drill-b.key on the dev machine must not
+    // turn the refusal into a hit (os.homedir() reads $HOME on POSIX).
+    const home = process.env.HOME;
+    process.env.HOME = mkdtempSync(join(tmpdir(), "cast-home-"));
+    try {
+      expect(() => keyFileFor("drill-b")).toThrow(
+        /no age key for drill-b.*CAST_AGE_KEY_FILE_DRILL_B.*age-drill-b\.key/s,
+      );
+    } finally {
+      process.env.HOME = home;
+    }
+  });
   it("falls back to a standing key on disk when one exists", () => {
     const home = process.env.HOME;
     const dir = mkdtempSync(join(tmpdir(), "cast-home-"));