diff --git a/packages/firefly-honeycomb/jest-setup.js b/packages/firefly-honeycomb/jest-setup.js
new file mode 100644
index 00000000..141e92bb
--- /dev/null
+++ b/packages/firefly-honeycomb/jest-setup.js
@@ -0,0 +1,6 @@
+// https://github.com/mswjs/msw/issues/1796
+
+import { TextDecoder, TextEncoder } from "node:util";
+
+global.TextEncoder = TextEncoder;
+global.TextDecoder = TextDecoder;
diff --git a/packages/firefly-honeycomb/jest.config.ts b/packages/firefly-honeycomb/jest.config.ts
index f1304f31..1a54a4ba 100644
--- a/packages/firefly-honeycomb/jest.config.ts
+++ b/packages/firefly-honeycomb/jest.config.ts
@@ -2,7 +2,9 @@ import type { Config } from "jest";
 import { swcConfig } from "./swc.jest.ts";
 
 const config: Config = {
-    testRegex: "/tests/*/.*\\.test\\.(ts|tsx)$",
+    // JSDOM is required for OTel instrumentation like "@opentelemetry/instrumentation-document-load".
+    testEnvironment: "jsdom",
+    testRegex: "/tests/*/.*\\.test\\.ts$",
     testPathIgnorePatterns: ["/node_modules/", "/dist/"],
     transformIgnorePatterns: [
         "node_modules/(?!.pnpm|memoize|mimic-function|@workleap/honeycomb)"
@@ -10,6 +12,7 @@ const config: Config = {
     transform: {
         "^.+\\.(js|ts|tsx)$": ["@swc/jest", swcConfig as Record<string, unknown>]
     },
+    setupFilesAfterEnv: ["<rootDir>/jest-setup.js"],
     cacheDirectory: "./node_modules/.cache/jest",
     verbose: true
 };
diff --git a/packages/firefly-honeycomb/package.json b/packages/firefly-honeycomb/package.json
index 7b6937d7..67448d86 100644
--- a/packages/firefly-honeycomb/package.json
+++ b/packages/firefly-honeycomb/package.json
@@ -63,6 +63,7 @@
         "@workleap/typescript-configs": "3.0.2",
         "eslint": "8.57.0",
         "jest": "29.7.0",
+        "jest-environment-jsdom": "29.7.0",
         "ts-node": "10.9.2",
         "typescript": "5.5.4"
     },
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index c6c400c1..cafeb6d3 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -364,6 +364,9 @@ importers:
       jest:
         specifier: 29.7.0
         version: 29.7.0(@types/node@22.10.7)(ts-node@10.9.2(@swc/core@1.10.7(@swc/helpers@0.5.15))(@types/node@22.10.7)(typescript@5.5.4))
+      jest-environment-jsdom:
+        specifier: 29.7.0
+        version: 29.7.0
       ts-node:
         specifier: 10.9.2
         version: 10.9.2(@swc/core@1.10.7)(@types/node@22.10.7)(typescript@5.5.4)