diff --git a/src/ida/IdaDiagnosticRedactor.test.ts b/src/ida/IdaDiagnosticRedactor.test.ts
index 188f9fb429..272f2a252a 100644
--- a/src/ida/IdaDiagnosticRedactor.test.ts
+++ b/src/ida/IdaDiagnosticRedactor.test.ts
@@ -62,6 +62,21 @@ describe("IDA diagnostic credential redaction", () => {
     const message = "Failed at /caller/input \t with ordinary whitespace";
     expect(redact(message)).toBe(message);
   });
+  it.each(["X-Caller-Value", "Authorization"])(
+    "redacts explicitly marked whitespace in %s independently of HTTP authentication",
+    (name) => {
+      const redact = createIdaDiagnosticRedactor({
+        url: "http://127.0.0.1:12345/mcp",
+        headers: { [name]: "\t" },
+        sensitive: { headers: [name.toLowerCase()], env: [] },
+        mode: "attached",
+        timeoutMs: 1000,
+      }).text;
+      expect(redact("input\tvalue")).toBe(
+        "input[redacted transport credential]value",
+      );
+    },
+  );
   it("does not reprocess the replacement marker as another credential", () => {
     const redact = createIdaDiagnosticRedactor({
       url: "http://127.0.0.1:12345/mcp",
diff --git a/src/ida/IdaRegistrationIdentity.ts b/src/ida/IdaRegistrationIdentity.ts
index b96b111d74..82dd0d4565 100644
--- a/src/ida/IdaRegistrationIdentity.ts
+++ b/src/ida/IdaRegistrationIdentity.ts
@@ -21,7 +21,11 @@ export const idaExplicitSensitiveValues = (
   if (config === undefined) return [];
   return "headers" in config
     ? Object.entries(config.headers)
-        .filter(([name]) => isSensitiveHeader(config, name))
+        .filter(([name]) =>
+          config.sensitive?.headers.some(
+            (selected) => selected.toLowerCase() === name.toLowerCase(),
+          ),
+        )
         .map(([, value]) => value)
     : Object.entries(config.env)
         .filter(([name]) => config.sensitive?.env.includes(name))