diff --git a/lib/config/migrations/custom/package-rules-migration.spec.ts b/lib/config/migrations/custom/package-rules-migration.spec.ts
index 2075a5727420fc89ff323676d49d63b97d6eb2b3..0c69d6261e9494e568aa1edd91039f4fd4843776 100644
--- a/lib/config/migrations/custom/package-rules-migration.spec.ts
+++ b/lib/config/migrations/custom/package-rules-migration.spec.ts
@@ -140,6 +140,10 @@ describe('config/migrations/custom/package-rules-migration', () => {
     expect(PackageRulesMigration).toMigrate(
       {
         packageRules: [
+          {
+            matchPackagePatterns: ['*'],
+            automerge: true,
+          },
           {
             matchPackagePatterns: ['foo', 'bar'],
             automerge: true,
@@ -153,6 +157,10 @@ describe('config/migrations/custom/package-rules-migration', () => {
       },
       {
         packageRules: [
+          {
+            automerge: true,
+            matchPackageNames: ['*'],
+          },
           {
             automerge: true,
             matchPackageNames: ['/foo/', '/bar/'],
diff --git a/lib/config/migrations/custom/package-rules-migration.ts b/lib/config/migrations/custom/package-rules-migration.ts
index 6b8aea4780ebbabb05b5a316fc23d6b12e8ce536..44d19e930cec6d46391a12201cd67c7073fd811d 100644
--- a/lib/config/migrations/custom/package-rules-migration.ts
+++ b/lib/config/migrations/custom/package-rules-migration.ts
@@ -78,7 +78,14 @@ function mergeMatchers(packageRule: PackageRule): PackageRule {
       const patterns = is.string(val) ? [val] : val;
       if (is.array(patterns, is.string)) {
         newPackageRule.matchPackageNames ??= [];
-        newPackageRule.matchPackageNames.push(...patterns.map((v) => `/${v}/`));
+        newPackageRule.matchPackageNames.push(
+          ...patterns.map((v) => {
+            if (v === '*') {
+              return '*';
+            }
+            return `/${v}/`;
+          }),
+        );
       }
       delete newPackageRule.matchPackagePatterns;
     }