diff --git a/.github/workflows/backward-compatibility.yml b/.github/workflows/backward-compatibility.yml
index 5411d5b9e3..0233e1e422 100644
--- a/.github/workflows/backward-compatibility.yml
+++ b/.github/workflows/backward-compatibility.yml
@@ -6,13 +6,13 @@ on:
   pull_request:
   push:
     branches:
-      - "1.11.x"
+      - "1.12.x"
     paths:
       - 'src/**'
       - '.github/workflows/backward-compatibility.yml'
 
 env:
-  COMPOSER_ROOT_VERSION: "1.11.x-dev"
+  COMPOSER_ROOT_VERSION: "1.12.x-dev"
 
 concurrency:
   group: bc-${{ github.head_ref || github.run_id }} # will be canceled on subsequent pushes in pull requests but not branches
diff --git a/.github/workflows/build-issue-bot.yml b/.github/workflows/build-issue-bot.yml
index 4769c56165..278470b466 100644
--- a/.github/workflows/build-issue-bot.yml
+++ b/.github/workflows/build-issue-bot.yml
@@ -9,13 +9,13 @@ on:
       - '.github/workflows/build-issue-bot.yml'
   push:
     branches:
-      - "1.11.x"
+      - "1.12.x"
     paths:
       - 'issue-bot/**'
       - '.github/workflows/build-issue-bot.yml'
 
 env:
-  COMPOSER_ROOT_VERSION: "1.11.x-dev"
+  COMPOSER_ROOT_VERSION: "1.12.x-dev"
 
 concurrency:
   group: build-issue-bot-${{ github.head_ref || github.run_id }} # will be canceled on subsequent pushes in pull requests but not branches
diff --git a/.github/workflows/changelog-generator.yml b/.github/workflows/changelog-generator.yml
index 1681e3a6e0..21971571f3 100644
--- a/.github/workflows/changelog-generator.yml
+++ b/.github/workflows/changelog-generator.yml
@@ -9,13 +9,13 @@ on:
       - '.github/workflows/changelog-generator.yml'
   push:
     branches:
-      - "1.11.x"
+      - "1.12.x"
     paths:
       - 'changelog-generator/**'
       - '.github/workflows/changelog-generator.yml'
 
 env:
-  COMPOSER_ROOT_VERSION: "1.11.x-dev"
+  COMPOSER_ROOT_VERSION: "1.12.x-dev"
 
 concurrency:
   group: changelog-${{ github.head_ref || github.run_id }} # will be canceled on subsequent pushes in pull requests but not branches
diff --git a/.github/workflows/checksum-phar.yml b/.github/workflows/checksum-phar.yml
index 1558436ad4..47256373d0 100644
--- a/.github/workflows/checksum-phar.yml
+++ b/.github/workflows/checksum-phar.yml
@@ -12,13 +12,13 @@ on:
       - '.github/workflows/checksum-phar.yml'
   push:
     branches:
-      - "1.11.x"
+      - "1.12.x"
     paths:
       - 'compiler/**'
       - '.github/workflows/checksum-phar.yml'
 
 env:
-  COMPOSER_ROOT_VERSION: "1.11.x-dev"
+  COMPOSER_ROOT_VERSION: "1.12.x-dev"
 
 concurrency:
   group: checksum-phar-${{ github.head_ref || github.run_id }} # will be canceled on subsequent pushes in pull requests but not branches
@@ -37,7 +37,7 @@ jobs:
         with:
           repository: phpstan/phpstan
           path: phpstan-dist
-          ref: 1.11.x
+          ref: 1.12.x
 
       - name: "Get info"
         id: info
@@ -101,14 +101,14 @@ jobs:
       - name: "Composer dump"
         run: "composer install --no-interaction --no-progress"
         env:
-          COMPOSER_ROOT_VERSION: "1.11.x-dev"
+          COMPOSER_ROOT_VERSION: "1.12.x-dev"
 
       - name: "Compile PHAR for checksum"
         working-directory: "compiler/build"
         run: "php box.phar compile --no-parallel"
         env:
           PHAR_CHECKSUM: "1"
-          COMPOSER_ROOT_VERSION: "1.11.x-dev"
+          COMPOSER_ROOT_VERSION: "1.12.x-dev"
 
       - name: "Re-sign PHAR"
         run: "php compiler/build/resign.php tmp/phpstan.phar"
diff --git a/.github/workflows/e2e-tests.yml b/.github/workflows/e2e-tests.yml
index 4ca9c86329..80f23291af 100644
--- a/.github/workflows/e2e-tests.yml
+++ b/.github/workflows/e2e-tests.yml
@@ -11,7 +11,7 @@ on:
       - 'issue-bot/**'
   push:
     branches:
-      - "1.11.x"
+      - "1.12.x"
     paths-ignore:
       - 'compiler/**'
       - 'apigen/**'
@@ -19,7 +19,7 @@ on:
       - 'issue-bot/**'
 
 env:
-  COMPOSER_ROOT_VERSION: "1.11.x-dev"
+  COMPOSER_ROOT_VERSION: "1.12.x-dev"
 
 concurrency:
   group: e2e-${{ github.head_ref || github.run_id }} # will be canceled on subsequent pushes in pull requests but not branches
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 14fbfbc500..b0393de109 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -6,10 +6,10 @@ on:
   pull_request:
   push:
     branches:
-      - "1.11.x"
+      - "1.12.x"
 
 env:
-  COMPOSER_ROOT_VERSION: "1.11.x-dev"
+  COMPOSER_ROOT_VERSION: "1.12.x-dev"
 
 concurrency:
   group: lint-${{ github.head_ref || github.run_id }} # will be canceled on subsequent pushes in pull requests but not branches
diff --git a/.github/workflows/phar.yml b/.github/workflows/phar.yml
index af601aa93b..c6c4934b44 100644
--- a/.github/workflows/phar.yml
+++ b/.github/workflows/phar.yml
@@ -6,9 +6,9 @@ on:
   pull_request:
   push:
     branches:
-      - "1.11.x"
+      - "1.12.x"
     tags:
-      - '1.11.*'
+      - '1.12.*'
 
 concurrency:
   group: phar-${{ github.ref }} # will be canceled on subsequent pushes in both branches and pull requests
@@ -77,14 +77,14 @@ jobs:
       - name: "Composer dump"
         run: "composer install --no-interaction --no-progress"
         env:
-          COMPOSER_ROOT_VERSION: "1.11.x-dev"
+          COMPOSER_ROOT_VERSION: "1.12.x-dev"
 
       - name: "Compile PHAR for checksum"
         working-directory: "compiler/build"
         run: "php box.phar compile --no-parallel"
         env:
           PHAR_CHECKSUM: "1"
-          COMPOSER_ROOT_VERSION: "1.11.x-dev"
+          COMPOSER_ROOT_VERSION: "1.12.x-dev"
 
       - name: "Re-sign PHAR"
         run: "php compiler/build/resign.php tmp/phpstan.phar"
@@ -107,30 +107,30 @@ jobs:
   integration-tests:
     if: github.event_name == 'pull_request'
     needs: compiler-tests
-    uses: phpstan/phpstan/.github/workflows/integration-tests.yml@1.11.x
+    uses: phpstan/phpstan/.github/workflows/integration-tests.yml@1.12.x
     with:
-      ref: 1.11.x
+      ref: 1.12.x
       phar-checksum: ${{needs.compiler-tests.outputs.checksum}}
 
   extension-tests:
     if: github.event_name == 'pull_request'
     needs: compiler-tests
-    uses: phpstan/phpstan/.github/workflows/extension-tests.yml@1.11.x
+    uses: phpstan/phpstan/.github/workflows/extension-tests.yml@1.12.x
     with:
-      ref: 1.11.x
+      ref: 1.12.x
       phar-checksum: ${{needs.compiler-tests.outputs.checksum}}
 
   other-tests:
     if: github.event_name == 'pull_request'
     needs: compiler-tests
-    uses: phpstan/phpstan/.github/workflows/other-tests.yml@1.11.x
+    uses: phpstan/phpstan/.github/workflows/other-tests.yml@1.12.x
     with:
-      ref: 1.11.x
+      ref: 1.12.x
       phar-checksum: ${{needs.compiler-tests.outputs.checksum}}
 
   commit:
     name: "Commit PHAR"
-    if: "github.repository_owner == 'phpstan' && (github.ref == 'refs/heads/1.11.x' || startsWith(github.ref, 'refs/tags/'))"
+    if: "github.repository_owner == 'phpstan' && (github.ref == 'refs/heads/1.12.x' || startsWith(github.ref, 'refs/tags/'))"
     needs: compiler-tests
     runs-on: "ubuntu-latest"
     timeout-minutes: 60
@@ -152,7 +152,7 @@ jobs:
           repository: phpstan/phpstan
           path: phpstan-dist
           token: ${{ secrets.PHPSTAN_BOT_TOKEN }}
-          ref: 1.11.x
+          ref: 1.12.x
 
       - name: "Get previous pushed dist commit"
         id: previous-commit
diff --git a/.github/workflows/reflection-golden-test.yml b/.github/workflows/reflection-golden-test.yml
index b3db1c394c..3c13f9205b 100644
--- a/.github/workflows/reflection-golden-test.yml
+++ b/.github/workflows/reflection-golden-test.yml
@@ -11,7 +11,7 @@ on:
       - 'issue-bot/**'
   push:
     branches:
-      - "1.11.x"
+      - "1.12.x"
     paths-ignore:
       - 'compiler/**'
       - 'apigen/**'
@@ -19,7 +19,7 @@ on:
       - 'issue-bot/**'
 
 env:
-  COMPOSER_ROOT_VERSION: "1.11.x-dev"
+  COMPOSER_ROOT_VERSION: "1.12.x-dev"
   REFLECTION_GOLDEN_TEST_FILE: "/tmp/reflection-golden.test"
   REFLECTION_GOLDEN_SYMBOLS_FILE: "/tmp/reflection-golden-symbols.txt"
 
diff --git a/.github/workflows/spelling.yml b/.github/workflows/spelling.yml
index 239668a718..b11ac9324b 100644
--- a/.github/workflows/spelling.yml
+++ b/.github/workflows/spelling.yml
@@ -6,7 +6,7 @@ on:
   pull_request:
   push:
     branches:
-      - "1.11.x"
+      - "1.12.x"
 
 jobs:
   typos:
diff --git a/.github/workflows/static-analysis.yml b/.github/workflows/static-analysis.yml
index 390bfa4b7e..d38dd2726e 100644
--- a/.github/workflows/static-analysis.yml
+++ b/.github/workflows/static-analysis.yml
@@ -9,13 +9,13 @@ on:
       - 'apigen/**'
   push:
     branches:
-      - "1.11.x"
+      - "1.12.x"
     paths-ignore:
       - 'compiler/**'
       - 'apigen/**'
 
 env:
-  COMPOSER_ROOT_VERSION: "1.11.x-dev"
+  COMPOSER_ROOT_VERSION: "1.12.x-dev"
 
 concurrency:
   group: sa-${{ github.head_ref || github.run_id }} # will be canceled on subsequent pushes in pull requests but not branches
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index f1a49d48f3..e86c7738fb 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -11,7 +11,7 @@ on:
       - 'issue-bot/**'
   push:
     branches:
-      - "1.11.x"
+      - "1.12.x"
     paths-ignore:
       - 'compiler/**'
       - 'apigen/**'
@@ -19,7 +19,7 @@ on:
       - 'issue-bot/**'
 
 env:
-  COMPOSER_ROOT_VERSION: "1.11.x-dev"
+  COMPOSER_ROOT_VERSION: "1.12.x-dev"
 
 concurrency:
   group: tests-${{ github.head_ref || github.run_id }} # will be canceled on subsequent pushes in pull requests but not branches