diff --git a/.changeset/plain-streets-flash.md b/.changeset/plain-streets-flash.md
new file mode 100644
index 0000000000..3a3b439139
--- /dev/null
+++ b/.changeset/plain-streets-flash.md
@@ -0,0 +1,6 @@
+---
+"@pnpm/lockfile.fs": patch
+"pnpm": patch
+---
+
+Fixed the `time` field in `pnpm-lock.yaml` being entirely wiped on every install. An incorrect dependency path format was used when matching entries to prune, causing all entries to always be removed.
diff --git a/lockfile/fs/src/lockfileFormatConverters.ts b/lockfile/fs/src/lockfileFormatConverters.ts
index c2315b4603..e0a2668135 100644
--- a/lockfile/fs/src/lockfileFormatConverters.ts
+++ b/lockfile/fs/src/lockfileFormatConverters.ts
@@ -1,5 +1,5 @@
 import { LOCKFILE_VERSION } from '@pnpm/constants'
-import { removeSuffix } from '@pnpm/dependency-path'
+import { refToRelative, removeSuffix } from '@pnpm/dependency-path'
 import type {
   LockfileFile,
   LockfileFileProjectResolvedDependencies,
@@ -124,22 +124,6 @@ function pruneTimeInLockfile (time: Record<string, string>, importers: Record<st
   return pickBy((_, depPath) => rootDepPaths.has(depPath), time)
 }
 
-function refToRelative (
-  reference: string,
-  pkgName: string
-): string | null {
-  if (reference.startsWith('link:')) {
-    return null
-  }
-  if (reference.startsWith('file:')) {
-    return reference
-  }
-  if (!reference.includes('/') || !reference.replace(/(?:\([^)]+\))+$/, '').includes('/')) {
-    return `/${pkgName}@${reference}`
-  }
-  return reference
-}
-
 export function convertToLockfileObject (lockfile: LockfileFile): LockfileObject {
   const { importers, ...rest } = lockfile
 
diff --git a/lockfile/fs/test/normalizeLockfile.test.ts b/lockfile/fs/test/normalizeLockfile.test.ts
index 463858aa35..bf7106f38e 100644
--- a/lockfile/fs/test/normalizeLockfile.test.ts
+++ b/lockfile/fs/test/normalizeLockfile.test.ts
@@ -57,10 +57,10 @@ test('redundant fields are removed from "time"', () => {
       },
     },
     time: {
-      '/bar@1.0.0': '2021-02-11T22:54:29.120Z',
-      '/foo@1.0.0': '2021-02-11T22:54:29.120Z',
-      '/qar@1.0.0': '2021-02-11T22:54:29.120Z',
-      '/zoo@1.0.0': '2021-02-11T22:54:29.120Z',
+      'bar@1.0.0': '2021-02-11T22:54:29.120Z',
+      'foo@1.0.0': '2021-02-11T22:54:29.120Z',
+      'qar@1.0.0': '2021-02-11T22:54:29.120Z',
+      'zoo@1.0.0': '2021-02-11T22:54:29.120Z',
     },
   })).toStrictEqual({
     lockfileVersion: LOCKFILE_VERSION,
@@ -87,9 +87,9 @@ test('redundant fields are removed from "time"', () => {
       },
     },
     time: {
-      '/bar@1.0.0': '2021-02-11T22:54:29.120Z',
-      '/foo@1.0.0': '2021-02-11T22:54:29.120Z',
-      '/qar@1.0.0': '2021-02-11T22:54:29.120Z',
+      'bar@1.0.0': '2021-02-11T22:54:29.120Z',
+      'foo@1.0.0': '2021-02-11T22:54:29.120Z',
+      'qar@1.0.0': '2021-02-11T22:54:29.120Z',
     },
   })
 })