diff --git a/packages/adapter-utils/src/paperclip-api-launcher.test.ts b/packages/adapter-utils/src/paperclip-api-launcher.test.ts
index c68664fef3a..8c3b8980ca7 100644
--- a/packages/adapter-utils/src/paperclip-api-launcher.test.ts
+++ b/packages/adapter-utils/src/paperclip-api-launcher.test.ts
@@ -96,6 +96,28 @@ describe("paperclip-api helper", () => {
     expect(request.body).toBe('{"body":"status"}');
   });
 
+  it("keeps a caller's lowercase content-type header as the only Content-Type header sent", async () => {
+    const result = await exec(
+      bin,
+      ["POST", "/api/issues/PAP-1/comments", "-H", "content-type: text/plain", "-d", "hello"],
+      { env: runEnv() },
+    );
+    expect(JSON.parse(result.stdout)).toEqual({ ok: true });
+    const request = configured.requests[0]!;
+    expect(request.headers["content-type"]).toBe("text/plain");
+  });
+
+  it("keeps a caller's lowercase x-paperclip-run-id header as the only X-Paperclip-Run-Id header sent", async () => {
+    const result = await exec(
+      bin,
+      ["POST", "/api/issues/PAP-1/comments", "-H", "x-paperclip-run-id: caller-run-id", "-d", '{"body":"status"}'],
+      { env: runEnv() },
+    );
+    expect(JSON.parse(result.stdout)).toEqual({ ok: true });
+    const request = configured.requests[0]!;
+    expect(request.headers["x-paperclip-run-id"]).toBe("caller-run-id");
+  });
+
   it("never puts the bearer on the command line", async () => {
     const args = ["POST", "/api/issues/PAP-1/comments", "-d", '{"body":"status"}'];
     expect(args.join(" ")).not.toContain(SENTINEL_BEARER);
diff --git a/packages/adapter-utils/src/paperclip-api-launcher.ts b/packages/adapter-utils/src/paperclip-api-launcher.ts
index c9c265e1a6d..dec38a7c843 100644
--- a/packages/adapter-utils/src/paperclip-api-launcher.ts
+++ b/packages/adapter-utils/src/paperclip-api-launcher.ts
@@ -218,9 +218,9 @@ async function main() {
     headers['Content-Type'] = multipart.contentType;
   } else if (parsed.bodySpec !== undefined) {
     body = await resolveBodySpec(parsed.bodySpec);
-    if (!('Content-Type' in headers)) headers['Content-Type'] = 'application/json';
+    if (!hasHeaderNamed(headers, 'content-type')) headers['Content-Type'] = 'application/json';
   }
-  if (process.env.PAPERCLIP_RUN_ID && !('X-Paperclip-Run-Id' in headers)) headers['X-Paperclip-Run-Id'] = process.env.PAPERCLIP_RUN_ID;
+  if (process.env.PAPERCLIP_RUN_ID && !hasHeaderNamed(headers, 'x-paperclip-run-id')) headers['X-Paperclip-Run-Id'] = process.env.PAPERCLIP_RUN_ID;
   // Set once, here. Nothing above this line can add or change this header.
   headers['Authorization'] = 'Bearer ' + bearer;