diff --git a/.changeset/strange-eagles-nail.md b/.changeset/strange-eagles-nail.md
new file mode 100644
index 0000000000..3560beef9e
--- /dev/null
+++ b/.changeset/strange-eagles-nail.md
@@ -0,0 +1,6 @@
+---
+"@pnpm/core": patch
+"pnpm": patch
+---
+
+Don't break lockfile v6 on repeat install if `use-lockfile-v6` is not set to `true`.
diff --git a/pkg-manager/core/src/install/extendInstallOptions.ts b/pkg-manager/core/src/install/extendInstallOptions.ts
index c47fead349..8021b445f4 100644
--- a/pkg-manager/core/src/install/extendInstallOptions.ts
+++ b/pkg-manager/core/src/install/extendInstallOptions.ts
@@ -120,7 +120,7 @@ export interface StrictInstallOptions {
   allProjects: ProjectOptions[]
   resolveSymlinksInInjectedDirs: boolean
   dedupeDirectDeps: boolean
-  useLockfileV6: boolean
+  useLockfileV6?: boolean
 }
 
 export type InstallOptions =
@@ -207,7 +207,6 @@ const defaults = async (opts: InstallOptions) => {
     resolveSymlinksInInjectedDirs: false,
     dedupeDirectDeps: false,
     resolvePeersFromWorkspaceRoot: false,
-    useLockfileV6: false,
   } as StrictInstallOptions
 }
 
diff --git a/pkg-manager/core/src/install/index.ts b/pkg-manager/core/src/install/index.ts
index 7cb4502e66..ea7b9b481a 100644
--- a/pkg-manager/core/src/install/index.ts
+++ b/pkg-manager/core/src/install/index.ts
@@ -279,6 +279,9 @@ export async function mutateModules (
         path: path.join(opts.lockfileDir, patchFile.path),
       }), patchedDependencies)
       : undefined
+    if (opts.useLockfileV6 == null) {
+      opts.useLockfileV6 = ctx.wantedLockfile.lockfileVersion.toString().startsWith('6.')
+    }
     let needsFullResolution = !maybeOpts.ignorePackageManifest &&
       lockfileIsUpToDate(ctx.wantedLockfile, {
         overrides: opts.overrides,
@@ -879,7 +882,7 @@ const _installInContext: InstallFunction = async (projects, ctx, opts) => {
     : newLockfile
 
   if (opts.updateLockfileMinorVersion) {
-    if (opts.useLockfileV6 || newLockfile.lockfileVersion.toString().startsWith('6.')) {
+    if (opts.useLockfileV6) {
       newLockfile.lockfileVersion = LOCKFILE_VERSION_V6
     } else {
       newLockfile.lockfileVersion = LOCKFILE_VERSION