diff --git a/.changeset/chilled-dancers-thank.md b/.changeset/chilled-dancers-thank.md
new file mode 100644
index 0000000000..36a35ba08e
--- /dev/null
+++ b/.changeset/chilled-dancers-thank.md
@@ -0,0 +1,6 @@
+---
+"@pnpm/resolve-dependencies": patch
+"pnpm": patch
+---
+
+In cases where both aliased and non-aliased dependencies exist to the same package, non-aliased dependencies will be used for resolving peer dependencies, addressing issue [#6588](https://github.com/pnpm/pnpm/issues/6588).
diff --git a/pkg-manager/core/test/install/peerDependencies.ts b/pkg-manager/core/test/install/peerDependencies.ts
index 12504ed01b..6a2b74fe9e 100644
--- a/pkg-manager/core/test/install/peerDependencies.ts
+++ b/pkg-manager/core/test/install/peerDependencies.ts
@@ -1443,6 +1443,20 @@ test('when there are several aliased dependencies of the same package, pick the
   expect(lockfile.packages['/@pnpm.e2e/abc@1.0.0(@pnpm.e2e/peer-c@2.0.0)']).toBeTruthy()
 })
 
+test('when there is an aliases dependency and a non-aliased one, prefer the non-aliased dependency to resolve peers', async () => {
+  prepareEmpty()
+
+  const opts = await testDefaults({ autoInstallPeers: false, strictPeerDependencies: false })
+  const manifest = await addDependenciesToPackage({}, [
+    '@pnpm.e2e/peer-c@1.0.0',
+    'peer-c@npm:@pnpm.e2e/peer-c@2.0.0',
+  ], opts)
+  await addDependenciesToPackage(manifest, ['@pnpm.e2e/abc@1.0.0'], opts)
+
+  const lockfile = await readYamlFile<any>(path.resolve(WANTED_LOCKFILE)) // eslint-disable-line
+  expect(lockfile.packages['/@pnpm.e2e/abc@1.0.0(@pnpm.e2e/peer-c@1.0.0)']).toBeTruthy()
+})
+
 test('in a subdependency, when there are several aliased dependencies of the same package, pick the one with the highest version to resolve peers', async () => {
   prepareEmpty()
 
diff --git a/pkg-manager/resolve-dependencies/src/resolvePeers.ts b/pkg-manager/resolve-dependencies/src/resolvePeers.ts
index 711fe0c9ca..c22ce45c45 100644
--- a/pkg-manager/resolve-dependencies/src/resolvePeers.ts
+++ b/pkg-manager/resolve-dependencies/src/resolvePeers.ts
@@ -631,9 +631,9 @@ function toPkgByName<T extends PartialResolvedPackage> (nodes: Array<{ alias: st
 function updateParentRefs (parentRefs: ParentRefs, newAlias: string, pkg: ParentRef) {
   const existing = parentRefs[newAlias]
   if (existing) {
-    const existingHasAlias = existing.alias != null || existing.alias !== newAlias
+    const existingHasAlias = existing.alias != null && existing.alias !== newAlias
     if (!existingHasAlias) return
-    const newHasAlias = pkg.alias != null || pkg.alias !== newAlias
+    const newHasAlias = pkg.alias != null && pkg.alias !== newAlias
     if (newHasAlias && semver.gte(existing.version, pkg.version)) return
   }
   parentRefs[newAlias] = pkg