diff --git a/.github/workflows/build-and-deploy.yml b/.github/workflows/build-and-deploy.yml
index aab82b8..67de9fc 100644
--- a/.github/workflows/build-and-deploy.yml
+++ b/.github/workflows/build-and-deploy.yml
@@ -12,7 +12,7 @@ jobs:
     - uses: actions/checkout@v2
     - uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: "3.10"
     - name: install dependencies
       run: |
         python -m pip install --upgrade pip
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 244d398..1b511fa 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -9,22 +9,19 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - python: 3.8
+          - python: "3.11"
             toxenv: flake8
             os: ubuntu-latest
-          - python: 3.8
+          - python: "3.11"
             toxenv: mypy
             os: ubuntu-latest
-          - python: 3.8
+          - python: "3.11"
             toxenv: pylint
             os: ubuntu-latest
-          - python: 3.8
+          - python: "3.11"
             toxenv: black
             os: ubuntu-latest
 
-          - python: 3.7
-            toxenv: py37
-            os: ubuntu-latest
           - python: 3.8
             toxenv: py38
             os: ubuntu-latest
@@ -37,25 +34,28 @@ jobs:
           - python: "3.11"
             toxenv: py311
             os: ubuntu-latest
-          - python: pypy-3.7
-            toxenv: pypy37
+          - python: "3.12"
+            toxenv: py312
+            os: ubuntu-latest
+          - python: 'pypy3.9'
+            toxenv: pypy39
             os: ubuntu-latest
 
-          - python: 3.8
-            toxenv: py38
+          - python: "3.11"
+            toxenv: py311
             os: macos-latest
-          - python: 3.8
-            toxenv: py38
+          - python: "3.11"
+            toxenv: py311
             os: windows-latest
 
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{  matrix.python }}
       - name: install dependencies
-        run: python -m pip install --upgrade pip tox
+        run: python -m pip install --upgrade pip tox setuptools wheel
       - name: run
         env:
           TOXENV: ${{ matrix.toxenv }}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 33a8949..639c3ac 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -34,6 +34,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Changed
   - Functions for ascents and descents now take an optional argument to specify what step size to calculate.
   - Moved sorting functions from `permuta/bisc/perm_properties.py` to `permuta/patterns/perm.py`.
+  - If you pass an iterable (that is not a perm) to a contains method, then it will now raise an error. 
+  These should be passed with the splat '*'. 
 
 ## 2.0.3 - 2021-04-28
 ### Added
diff --git a/permuta/bisc/bisc.py b/permuta/bisc/bisc.py
index 9ecc5c3..29bb2e3 100644
--- a/permuta/bisc/bisc.py
+++ b/permuta/bisc/bisc.py
@@ -19,7 +19,6 @@
 
 
 def bisc(A, m, n=None, report=False):
-
     if isinstance(A, list):
         D = defaultdict(list)
         for perm in A:
@@ -56,7 +55,6 @@ def bisc(A, m, n=None, report=False):
 
 
 def auto_bisc(prop):
-
     L = 8  # Want to sanity check on at least S8, and one above n
     n = 4
     m = 2
@@ -274,7 +272,6 @@ def create_bisc_input(N, prop):
     A, B = {}, {}
 
     for n in range(N + 1):
-
         An, Bn = [], []
 
         for perm in Perm.of_length(n):
diff --git a/permuta/patterns/meshpatt.py b/permuta/patterns/meshpatt.py
index 724872f..a14b93c 100644
--- a/permuta/patterns/meshpatt.py
+++ b/permuta/patterns/meshpatt.py
@@ -27,7 +27,7 @@ def __init__(
             and 0 <= coordinate[0] <= len(self.pattern)
             and 0 <= coordinate[1] <= len(self.pattern)
             for coordinate in self.shading
-        )
+        ), "shadings should be 2-tuples with integers between 0 and len(pattern)"
 
     @classmethod
     def unrank(cls, pattern: Perm, number: int) -> "MeshPatt":
@@ -327,6 +327,11 @@ def add_decrease(self, pos: Tuple[int, int]) -> "MeshPatt":
         x, y = pos
         return self.add_point((x, y)).add_point((x + 1, y))
 
+    def _contains(self, patt: Patt) -> bool:
+        if isinstance(patt, Patt):
+            return any(True for _ in patt.occurrences_in(self))
+        raise TypeError("patt must be a Patt")
+
     def contains(self, *patts: Patt) -> bool:
         """Check if self contains all provided patterns.
 
@@ -336,7 +341,7 @@ def contains(self, *patts: Patt) -> bool:
             >>> MeshPatt(Perm((0,)), [(0, 1)]).contains(MeshPatt(Perm((0,)), []))
             True
         """
-        return all(patt in self for patt in patts)
+        return all(self._contains(patt) for patt in patts)
 
     def avoids(self, *patts: Patt) -> bool:
         """Check if self avoids all provided patterns.
@@ -351,7 +356,7 @@ def avoids(self, *patts: Patt) -> bool:
             >>> MeshPatt(Perm((0,)), [(0, 1)]).avoids(MeshPatt(Perm((0,)), []))
             False
         """
-        return all(patt not in self for patt in patts)
+        return all(not self._contains(patt) for patt in patts)
 
     def occurrences_in(self, patt: Patt, *args, **kwargs) -> Iterator[Tuple[int, ...]]:
         """
@@ -689,7 +694,7 @@ def rank(self) -> int:
             '0b1011101001100101'
         """
         n, res = len(self), 0
-        for (x, y) in self.shading:
+        for x, y in self.shading:
             res |= 1 << (x * (n + 1) + y)
         return res
 
@@ -845,5 +850,5 @@ def __ge__(self, other: object) -> bool:
 
     def __contains__(self, patt: object) -> bool:
         if isinstance(patt, Patt):
-            return any(True for _ in patt.occurrences_in(self))
-        return False
+            return self._contains(patt)
+        raise TypeError("patt must be a Patt")
diff --git a/permuta/patterns/patt.py b/permuta/patterns/patt.py
index 7796277..d0292e4 100644
--- a/permuta/patterns/patt.py
+++ b/permuta/patterns/patt.py
@@ -11,11 +11,11 @@ class Patt(abc.ABC):
 
     def avoided_by(self, *patts: "Patt") -> bool:
         """Check if self is avoided by all the provided patterns."""
-        return all(self not in patt for patt in patts)
+        return all(not patt.contains(self) for patt in patts)
 
     def contained_in(self, *patts: "Patt") -> bool:
         """Check if self is a pattern of all the provided patterns."""
-        return all(self in patt for patt in patts)
+        return all(patt.contains(self) for patt in patts)
 
     def count_occurrences_in(self, patt: "Patt") -> int:
         """Count the number of occurrences of self in the pattern."""
@@ -36,5 +36,10 @@ def get_perm(self) -> "Perm":
         """Get the permutation part of the pattern"""
 
     @abc.abstractmethod
-    def __contains__(self, patt: object) -> bool:
+    def _contains(self, patt: "Patt") -> bool:
         """Does pattern contains another?"""
+
+    contains = _contains
+
+    def __contains__(self, patt: "Patt") -> bool:
+        return self._contains(patt)
diff --git a/permuta/patterns/perm.py b/permuta/patterns/perm.py
index 1c24a84..2f5ab7e 100644
--- a/permuta/patterns/perm.py
+++ b/permuta/patterns/perm.py
@@ -2496,7 +2496,12 @@ def contains(self, *patts: "Patt") -> bool:
             >>> Perm((5, 3, 0, 4, 2, 1)).contains(pattern2, pattern3)
             False
         """
-        return all(patt in self for patt in patts)
+        return all(self._contains(patt) for patt in patts)
+
+    def _contains(self, patt: "Patt") -> bool:
+        if isinstance(patt, Patt):
+            return any(True for _ in patt.occurrences_in(self))
+        raise TypeError("patt must be a Patt")
 
     def avoids(self, *patts: "Patt") -> bool:
         """Check if self avoids patts.
@@ -2519,7 +2524,7 @@ def avoids(self, *patts: "Patt") -> bool:
             >>> Perm((5, 3, 0, 4, 2, 1)).avoids(pattern3, pattern4)
             True
         """
-        return all(patt not in self for patt in patts)
+        return all(not self._contains(patt) for patt in patts)
 
     def avoids_set(self, patts: Iterable["Patt"]) -> bool:
         """Check if self avoids patts for an iterable of patterns.
@@ -3027,5 +3032,5 @@ def __len__(self) -> int:
 
     def __contains__(self, patt: object) -> bool:
         if isinstance(patt, Patt):
-            return any(True for _ in patt.occurrences_in(self))
-        return False
+            return self._contains(patt)
+        raise TypeError("patt must be a Patt")
diff --git a/pyproject.toml b/pyproject.toml
index 01c7757..c459f89 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,5 @@
 [tool.black]
-target-version = ['py37']
+target-version = ['py310']
 include = '\.pyi?$'
 exclude = '''
 
diff --git a/tox.ini b/tox.ini
index db5a6fe..e6940f9 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,21 +6,20 @@
 [tox]
 envlist =
     flake8, mypy, pylint, black
-    py{37,38,39, 310, 311},
-    pypy37
+    py{39, 310, 311, 312},
+    pypy39
 
 [default]
-basepython=python3.8
+basepython=python3.11
 
 [testenv]
 description = run test
 basepython =
-    py37: python3.7
-    py38: python3.8
     py39: python3.9
     py310: python3.10
     py311: python3.11
-    pypy37: pypy3
+    py312: python3.12
+    pypy39: pypy3.9
 deps =
     pytest==7.2.0
     pytest-timeout==2.1.0