diff --git a/bun.lock b/bun.lock
index 5baa5c009f2..292cb1cfdf5 100644
--- a/bun.lock
+++ b/bun.lock
@@ -972,6 +972,7 @@
       "dependencies": {
         "@effect/opentelemetry": "catalog:",
         "@effect/platform-node": "catalog:",
+        "@effect/platform-node-shared": "catalog:",
         "@npmcli/arborist": "catalog:",
         "@npmcli/config": "10.8.1",
         "@opentelemetry/api": "1.9.0",
diff --git a/packages/sdk/script/verify-package.ts b/packages/sdk/script/verify-package.ts
index 054f94a7f72..03457d89b49 100644
--- a/packages/sdk/script/verify-package.ts
+++ b/packages/sdk/script/verify-package.ts
@@ -173,6 +173,10 @@ for (const module of modules) {
   const sdk = archives.get("@opencode-ai/sdk")
   if (!sdk) throw new Error("Packed SDK archive was not created")
   await $`npm install --ignore-scripts --no-audit --no-fund --package-lock=false ${sdk} wrangler@4.110.0`.cwd(consumer)
+  const runtimes = (await $`npm ls effect --all --parseable`.cwd(consumer).text()).trim().split("\n")
+  if (runtimes.length !== 1) {
+    throw new Error(`Packed SDK consumer resolved multiple Effect runtimes:\n${runtimes.join("\n")}`)
+  }
   await $`bun imports.mjs`.cwd(consumer)
   await $`bun --conditions=workerd imports.mjs`.cwd(consumer)
   await $`node_modules/.bin/wrangler deploy --dry-run --config wrangler.jsonc --outdir dist`.cwd(consumer)
diff --git a/packages/util/package.json b/packages/util/package.json
index c61568d7d0a..8117eba8a38 100644
--- a/packages/util/package.json
+++ b/packages/util/package.json
@@ -39,6 +39,7 @@
   "dependencies": {
     "@effect/opentelemetry": "catalog:",
     "@effect/platform-node": "catalog:",
+    "@effect/platform-node-shared": "catalog:",
     "@npmcli/arborist": "catalog:",
     "@npmcli/config": "10.8.1",
     "@opentelemetry/api": "1.9.0",