diff --git a/.github/workflows/doc.yml b/.github/workflows/doc.yml
index 4a832e6..e8f52fe 100644
--- a/.github/workflows/doc.yml
+++ b/.github/workflows/doc.yml
@@ -14,7 +14,7 @@ jobs:
     strategy:
       matrix:
         python-version: ["3.8"]
-        minizinc-version: ["2.7.2", "2.5.4"]
+        minizinc-version: ["2.7.6", "2.6.0"]
 
     env:
       MINIZINC_URL: https://github.com/MiniZinc/MiniZincIDE/releases/download/${{ matrix.minizinc-version }}/MiniZincIDE-${{ matrix.minizinc-version }}-x86_64.AppImage
diff --git a/.github/workflows/release-test.yml b/.github/workflows/release-test.yml
new file mode 100644
index 0000000..6591653
--- /dev/null
+++ b/.github/workflows/release-test.yml
@@ -0,0 +1,53 @@
+# This workflow will install Python dependencies, run tests and lint with a variety of Python versions
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions
+
+name: On release
+
+on:
+  pull_request:
+    branches: [ release ]
+
+jobs:
+  test:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
+        minizinc-version: ["2.7.6", "2.6.0"]
+
+    env:
+      MINIZINC_URL: https://github.com/MiniZinc/MiniZincIDE/releases/download/${{ matrix.minizinc-version }}/MiniZincIDE-${{ matrix.minizinc-version }}-x86_64.AppImage
+    steps:
+    - uses: actions/checkout@v3
+    - name: Add bin/ to PATH
+      run: |
+        mkdir -p ${{ github.workspace }}/bin
+        echo "${{ github.workspace }}/bin" >> $GITHUB_PATH
+    - name: Install libfuse (AppImage dependency)
+      run: |
+        sudo apt-get update
+        sudo apt-get install libfuse2
+        sudo apt-get install libegl1
+    - name: Cache MiniZinc
+      id: cache-minizinc
+      uses: actions/cache@v3
+      with:
+        path: ${{ github.workspace }}/bin/minizinc
+        key: ${{ env.MINIZINC_URL }}
+    - name: Download MiniZinc
+      if: steps.cache-minizinc.outputs.cache-hit != 'true'
+      run: |
+        sudo curl -o ${{ github.workspace }}/bin/minizinc -L $MINIZINC_URL
+        sudo chmod +x ${{ github.workspace }}/bin/minizinc
+        minizinc --version
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v4
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install nox
+      run: |
+        pip install nox
+    - name: Test
+      run: |
+        nox
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 451d64b..27e4362 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -13,8 +13,8 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11"]
-        minizinc-version: ["2.7.2", "2.5.4"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
+        minizinc-version: ["2.7.6", "2.6.0"]
 
     env:
       MINIZINC_URL: https://github.com/MiniZinc/MiniZincIDE/releases/download/${{ matrix.minizinc-version }}/MiniZincIDE-${{ matrix.minizinc-version }}-x86_64.AppImage
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f304eb6..1d12913 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -14,7 +14,7 @@ jobs:
     strategy:
       matrix:
         python-version: ["3.8"]
-        minizinc-version: ["2.7.2", "2.5.4"]
+        minizinc-version: ["2.7.6", "2.6.0"]
 
     env:
       MINIZINC_URL: https://github.com/MiniZinc/MiniZincIDE/releases/download/${{ matrix.minizinc-version }}/MiniZincIDE-${{ matrix.minizinc-version }}-x86_64.AppImage
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 40f6da8..53ae964 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -1,6 +1,6 @@
 version: 2
 build:
-  os: "ubuntu-20.04"
+  os: "ubuntu-22.04"
   tools:
     python: "3.8"
   jobs:
diff --git a/README.md b/README.md
index 2eff09b..31bd66c 100644
--- a/README.md
+++ b/README.md
@@ -23,7 +23,7 @@ programs.
 
 ### Prerequisites
 
-- You should have minizinc 2.5.4+ install and have it executable in ``$PATH``.
+- You should have minizinc 2.6.0+ install and have it executable in ``$PATH``.
 You can download it from [official site](https://www.minizinc.org/).
 - Python 3.8+
 
diff --git a/changelog.md b/changelog.md
index 6f5a4d4..b3dae5b 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,10 +1,16 @@
+## 0.4.2
+#### CI changes
+- use minizinc 2.7.6 as maximum version in CI (as in minizinc-python)
+- use minizinc 2.6.0 as minimum version in CI (as in minizinc-python)
+#### Python interpreters support
+- add 3.12 CPython
+
 ## 0.4.1
 #### Added
 - ``table`` constraint
 - ``contains`` method for arrays and sets, to check if elem presented
   in collection
 - ``except_`` argument to ``all_different`` constraint
-#### Changed
 
 ## 0.4.0
 #### Added
diff --git a/setup.py b/setup.py
index d97a985..0608299 100644
--- a/setup.py
+++ b/setup.py
@@ -10,7 +10,7 @@
 setup(
     name="zython",
     version=read_version(),
-    python_requires=">=3.7",
+    python_requires=">=3.8",
     author="Artsiom Kaltovich",
     author_email="kaltovichartyom@gmail.com",
     description="Express constraint programming problem with python and solve it with minizinc",
@@ -30,6 +30,7 @@
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
+        "Programming Language :: Python :: 3.12",
         "Programming Language :: Python :: Implementation :: CPython",
         "License :: OSI Approved :: Mozilla Public License 2.0 (MPL 2.0)",
         "Intended Audience :: Developers",
diff --git a/zython/_compile/zinc/flags.py b/zython/_compile/zinc/flags.py
index 87e5f9c..e440b28 100644
--- a/zython/_compile/zinc/flags.py
+++ b/zython/_compile/zinc/flags.py
@@ -1,6 +1,6 @@
 import enum
-from collections import UserDict
 from functools import partial
+from typing import Callable, Dict
 
 from zython._compile.zinc.types import SourceCode
 
@@ -22,30 +22,22 @@ class Flags(enum.Flag):
     float_used = enum.auto()
 
 
-FLAG_TO_SRC_PREFIX = {
-    Flags.alldifferent: 'include "alldifferent.mzn";',
-    Flags.alldifferent_except_0: 'include "alldifferent_except_0.mzn";',
-    Flags.alldifferent_except: 'include "alldifferent_except.mzn";',
-    Flags.all_equal: 'include "all_equal.mzn";',
-    Flags.nvalue: 'include "nvalue_fn.mzn";',
-    Flags.circuit: 'include "circuit.mzn";',
-    Flags.increasing: 'include "increasing.mzn";',
-    Flags.strictly_increasing: 'include "strictly_increasing.mzn";',
-    Flags.decreasing: 'include "decreasing.mzn";',
-    Flags.strictly_decreasing: 'include "strictly_decreasing.mzn";',
-    Flags.cumulative: 'include "cumulative.mzn";',
-    Flags.table: 'include "table.mzn";',
-}
-
-
 def append(src: SourceCode, line: str):
     src.appendleft(line)
 
 
-class FlagProcessors(UserDict):
-    def __init__(self):
-        super().__init__()
-        self[Flags.float_used] = None
-
-    def __missing__(self, key):
-        return partial(append, line=FLAG_TO_SRC_PREFIX[key])
+FLAG_PROCESSORS: Dict[Flags, Callable[[SourceCode], None]] = {
+    Flags.alldifferent: partial(append, line='include "alldifferent.mzn";'),
+    Flags.alldifferent_except_0: partial(append, line='include "alldifferent_except_0.mzn";'),
+    Flags.alldifferent_except: partial(append, line='include "alldifferent_except.mzn";'),
+    Flags.all_equal: partial(append, line='include "all_equal.mzn";'),
+    Flags.nvalue: partial(append, line='include "nvalue_fn.mzn";'),
+    Flags.circuit: partial(append, line='include "circuit.mzn";'),
+    Flags.increasing: partial(append, line='include "increasing.mzn";'),
+    Flags.strictly_increasing: partial(append, line='include "strictly_increasing.mzn";'),
+    Flags.decreasing: partial(append, line='include "decreasing.mzn";'),
+    Flags.strictly_decreasing: partial(append, line='include "strictly_decreasing.mzn";'),
+    Flags.cumulative: partial(append, line='include "cumulative.mzn";'),
+    Flags.table: partial(append, line='include "table.mzn";'),
+    Flags.float_used: lambda x: x,
+}
diff --git a/zython/_compile/zinc/zinc.py b/zython/_compile/zinc/zinc.py
index 8e4890b..43dadee 100644
--- a/zython/_compile/zinc/zinc.py
+++ b/zython/_compile/zinc/zinc.py
@@ -3,7 +3,7 @@
 from typing import Set
 
 from zython._compile.ir import IR
-from zython._compile.zinc.flags import Flags, FlagProcessors
+from zython._compile.zinc.flags import Flags, FLAG_PROCESSORS
 from zython._compile.zinc.to_str import to_str, _binary_op, _get_array_shape_decl
 from zython._compile.zinc.types import SourceCode
 from zython.operations.constraint import Constraint
@@ -15,21 +15,18 @@
 def to_zinc(ir: IR):
     result: SourceCode = deque()
     flags: Set[Flags] = set()
-    flag_processors = FlagProcessors()
     _process_enums(ir, result, flags)
     _process_pars(ir, result, flags)
     _process_vars(ir, result, flags)
     _process_constraints(ir, result, flags)
     _process_how_to_solve(ir, result)
-    _process_flags(flag_processors, flags, result)
+    _process_flags(flags, result)
     return "\n".join(result)
 
 
-def _process_flags(flag_processors: FlagProcessors, flags, result: SourceCode):
+def _process_flags(flags, result: SourceCode):
     for flag in flags:
-        pr = flag_processors.get(flag)
-        if pr:
-            pr(result)
+        FLAG_PROCESSORS[flag](result)
 
 
 def _process_enums(ir: IR, result: SourceCode, flags: Set[Flags]) -> None: