diff --git a/.changeset/quiet-links-sync.md b/.changeset/quiet-links-sync.md
new file mode 100644
index 0000000..f388411
--- /dev/null
+++ b/.changeset/quiet-links-sync.md
@@ -0,0 +1,5 @@
+---
+"packref": patch
+---
+
+Fix `packref sync` in monorepos that have private workspace packages with no `version` field. Packref does not show a manifest parse error for these packages now. Packref also stops at the nearest installed package, and does not use a version from a different package with the same name in a parent `node_modules`.
diff --git a/src/lib/manifests/__tests__/javascript.test.ts b/src/lib/manifests/__tests__/javascript.test.ts
index 0cb1668..117ce31 100644
--- a/src/lib/manifests/__tests__/javascript.test.ts
+++ b/src/lib/manifests/__tests__/javascript.test.ts
@@ -1,6 +1,6 @@
 import type * as FileSystem from "effect/FileSystem"
 import type * as Path from "effect/Path"
-import { mkdir, mkdtemp, rm, writeFile } from "node:fs/promises"
+import { mkdir, mkdtemp, rm, symlink, writeFile } from "node:fs/promises"
 import { tmpdir } from "node:os"
 import { join } from "node:path"
 import * as NodeServices from "@effect/platform-node/NodeServices"
@@ -485,6 +485,69 @@ importers:
     expect(dependencies[0]?.exactVersion).toBe("4.0.0-beta.55")
   })
 
+  it("stops at the nearest installed package when it has no version", async () => {
+    const workspaceRoot = await makeTempDirectory()
+    const projectPath = join(workspaceRoot, "apps", "web")
+    const workspacePackagePath = join(workspaceRoot, "tooling", "linting")
+    await mkdir(projectPath, { recursive: true })
+    await mkdir(workspacePackagePath, { recursive: true })
+    await writeFile(
+      join(projectPath, "package.json"),
+      JSON.stringify({
+        dependencies: {
+          effect: "^4.0.0-beta.50",
+        },
+        devDependencies: {
+          "@tooling/linting": "workspace:*",
+        },
+      })
+    )
+    await writeFile(
+      join(workspacePackagePath, "package.json"),
+      JSON.stringify({ name: "@tooling/linting", private: true })
+    )
+    await mkdir(join(projectPath, "node_modules", "@tooling"), { recursive: true })
+    await symlink(workspacePackagePath, join(projectPath, "node_modules", "@tooling", "linting"))
+    await mkdir(join(workspaceRoot, "node_modules", "@tooling", "linting"), { recursive: true })
+    await writeFile(
+      join(workspaceRoot, "node_modules", "@tooling", "linting", "package.json"),
+      JSON.stringify({ name: "@tooling/linting", version: "2.0.0" })
+    )
+    await mkdir(join(projectPath, "node_modules", "effect"), { recursive: true })
+    await writeFile(
+      join(projectPath, "node_modules", "effect", "package.json"),
+      JSON.stringify({ version: "4.0.0-beta.55" })
+    )
+
+    const dependencies = await run(readJavascriptManifest(projectPath))
+
+    expect(dependencies.map(({ exactVersion, name }) => [name, exactVersion])).toEqual([
+      ["effect", "4.0.0-beta.55"],
+      ["@tooling/linting", undefined],
+    ])
+  })
+
+  it("keeps the installed version for a local path dependency", async () => {
+    const projectPath = await makeTempDirectory()
+    await writeFile(
+      join(projectPath, "package.json"),
+      JSON.stringify({
+        dependencies: {
+          example: "file:../example",
+        },
+      })
+    )
+    await mkdir(join(projectPath, "node_modules", "example"), { recursive: true })
+    await writeFile(
+      join(projectPath, "node_modules", "example", "package.json"),
+      JSON.stringify({ name: "example", version: "1.0.0" })
+    )
+
+    const dependencies = await run(readJavascriptManifest(projectPath))
+
+    expect(dependencies[0]?.exactVersion).toBe("1.0.0")
+  })
+
   it("reports no dependency for installed packages absent from the manifest", async () => {
     const projectPath = await makeTempDirectory()
     await writeFile(
diff --git a/src/lib/manifests/javascript.ts b/src/lib/manifests/javascript.ts
index 963e68d..bf2e4ee 100644
--- a/src/lib/manifests/javascript.ts
+++ b/src/lib/manifests/javascript.ts
@@ -34,7 +34,7 @@ export const JavascriptPackageManifestSchema = Schema.StructWithRest(
 
 const InstalledPackageSchema = Schema.StructWithRest(
   Schema.Struct({
-    version: Schema.String,
+    version: Schema.optional(Schema.String),
   }),
   [Schema.Record(Schema.String, Schema.Unknown)]
 )
@@ -485,10 +485,15 @@ const readNodeModulesVersion = Effect.fn("readNodeModulesVersion")(function* (
         toManifestParseError(packageJsonPath)
       )
 
-      return valid(manifest.version) === null
-        ? Result.fail(void 0)
-        : Result.succeed(manifest.version)
+      // Like Node resolution, stop at the nearest installed package even if it has no version.
+      return Result.succeed(manifest.version)
     })
+  ).pipe(
+    Effect.map(
+      Option.filter(
+        (version): version is string => version !== undefined && valid(version) !== null
+      )
+    )
   )
 })