diff --git a/.github/workflows/conda.yml b/.github/workflows/conda.yml
index d426ab2..236d9d6 100644
--- a/.github/workflows/conda.yml
+++ b/.github/workflows/conda.yml
@@ -1,66 +1,63 @@
 name: ssqueezepy CI
 
 on:
-    workflow_dispatch:
-    
-    pull_request:
-      paths:
-        - "ssqueezepy/*"
-        - "tests/*"
-        - ".github/workflows/*"
-        - ".coveragerc"
-        - "requirements.txt"
-        - "requirements-dev.txt"
-    
-    push:
-      branches:
-        - master
+  workflow_dispatch:
+
+  pull_request:
+    paths:
+      - "ssqueezepy/*"
+      - "tests/*"
+      - ".github/workflows/*"
+      - ".coveragerc"
+      - "requirements.txt"
+      - "requirements-dev.txt"
+
+  push:
+    branches:
+      - master
 
 jobs:
-    build-conda:
-        if: "! contains(toJSON(github.event.commits.*.message), '[skip ci]')"
-        runs-on: ubuntu-latest
+  build-mamba:
+    if: "! contains(toJSON(github.event.commits.*.message), '[skip ci]')"
+    runs-on: ubuntu-latest
 
-        strategy:
-            matrix:
-                python-version: [3.7]
+    strategy:
+      matrix:
+        python-version: [3.10]
 
-        steps:
-            - uses: actions/checkout@v3
-            
-            - name: Add Conda to path
-              run: echo $CONDA >> $GITHUB_PATH
-            
-            - name: Install Conda environment with Micromamba
-              uses: mamba-org/provision-with-micromamba@main
-              with:
-                cache-downloads: true
-                cache-env: true
-                environment-file: environment.yaml
-                extra-specs: |
-                  python=${{ matrix.python-version }}
-                  
-            - name: additional setup
-              shell: bash -l {0}
-              run: |
-                  conda run python3 -m pip install --upgrade pip
-                  conda run python3 -m pip install -r requirements.txt
-                  conda run python3 -m pip install -r requirements-dev.txt
+    steps:
+      - uses: actions/checkout@v4
 
-            - name: Set up ssqueezepy
-              run: conda run pip install -e .
+      - name: Setup Micromamba environment
+        uses: mamba-org/setup-micromamba@v1
+        with:
+          micromamba-version: '1.5.8-0'
+          environment-file: environment.yaml
+          init-shell: bash
+          cache-environment: true
+          post-cleanup: 'all'
+
+      - name: additional setup
+        shell: bash -l {0}
+        run: |
+            python -m pip install --upgrade pip
+            python -m pip install -r requirements.txt
+            python -m pip install -r requirements-dev.txt
+
+      - name: Set up ssqueezepy
+        run: pip install -e .
+
+      - name: Test
+        shell: bash -l {0}
+        run: >
+            pycodestyle --max-line-length=85 
+            --ignore=E221,E241,E225,E226,E402,E722,E741,E272,E266,E302,E731,E702,E201,E129,E203,E202,W503,W504 
+            ssqueezepy
+            
+            pytest tests/ -s --cov=ssqueezepy --cov-report=xml
 
-            - name: Test
-              shell: bash -l {0}
-              run: >
-                  conda run pycodestyle --max-line-length=85 
-                  --ignore=E221,E241,E225,E226,E402,E722,E741,E272,E266,E302,E731,E702,E201,E129,E203,E202,W503,W504 
-                  ssqueezepy
-                  
-                  conda run pytest tests/ -s --cov=ssqueezepy --cov-report=xml
-                  
-            - name: codecov upload coverage
-              uses: codecov/codecov-action@v1
-              with:
-                token: ${{ secrets.CODECOV_TOKEN }}
-                directory: ./
+      - name: codecov upload coverage
+        uses: codecov/codecov-action@v1
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          directory: ./
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 876b52e..95773af 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,10 @@
+### 0.6.5
+
+#### FIXES
+ - CuPy deprecation fix (update methods to be compatible with latest CuPy)
+ - `imp` -> `importlib` (Python deprecation)
+ - Github Actions changes: use fully micromamba; actions v4; py 3.7 -> 3.10; 
+
 ### 0.6.4
 
 #### FEATURES
diff --git a/environment.yaml b/environment.yaml
index 2ad449a..f325e46 100644
--- a/environment.yaml
+++ b/environment.yaml
@@ -9,7 +9,7 @@ dependencies:
   - pytest-cov
   - pycodestyle
   - pip
-  - python >=3.7
+  - python >=3.10
   - numpy
   - scipy 
   - matplotlib 
diff --git a/ssqueezepy/__init__.py b/ssqueezepy/__init__.py
index 932ffe3..ce69f5d 100644
--- a/ssqueezepy/__init__.py
+++ b/ssqueezepy/__init__.py
@@ -27,7 +27,7 @@
 """
 
 
-__version__ = '0.6.4'
+__version__ = '0.6.5'
 __title__ = 'ssqueezepy'
 __author__ = 'John Muradeli'
 __license__ = __doc__
diff --git a/ssqueezepy/utils/backend.py b/ssqueezepy/utils/backend.py
index 0659b3d..64f1972 100644
--- a/ssqueezepy/utils/backend.py
+++ b/ssqueezepy/utils/backend.py
@@ -106,20 +106,14 @@ def __init__(self):
         self.dtype = _TensorDummy
 
 
-class _Util():
-    """For wrapper: `@cp._util.memoize`."""
+class CupyDummy():
+    """Dummy class with dummy attributes."""
     def memoize(self, *args, **kwargs):
         def wrap(fn):
             return fn
         return wrap
 
 
-class CupyDummy():
-    """Dummy class with dummy attributes."""
-    def __init__(self):
-        self._util = _Util()
-
-
 class _Q():
     """Class for accessing `numpy` or `torch` attributes according to `USE_GPU()`.
     """
diff --git a/ssqueezepy/utils/gpu_utils.py b/ssqueezepy/utils/gpu_utils.py
index 4743703..8169275 100644
--- a/ssqueezepy/utils/gpu_utils.py
+++ b/ssqueezepy/utils/gpu_utils.py
@@ -14,10 +14,10 @@ def _run_on_gpu(kernel, grid, block, *args, **kwargs):
        stream=Stream(ptr=torch.cuda.current_stream().cuda_stream))
 
 
-@cp._util.memoize(for_each_device=True)
+@cp.memoize(for_each_device=True)
 def load_kernel(kernel_name, code, **kwargs):
     code = Template(code).substitute(**kwargs)
-    kernel_code = cp.cuda.compile_with_cache(code)
+    kernel_code = cp.RawModule(code=code)
     return kernel_code.get_function(kernel_name)
 
 
diff --git a/tests/fft_test.py b/tests/fft_test.py
index 489a5e0..9c1b5d8 100644
--- a/tests/fft_test.py
+++ b/tests/fft_test.py
@@ -416,7 +416,7 @@ def test_buffer():
 
 
 def test_ssq_stft():
-    N = 256
+    N = 512
     tsigs = TestSignals(N=N)
     gpu_atol = 1e-5
 
@@ -578,16 +578,17 @@ def test_ssq_cwt_batched():
             os.environ['SSQ_GPU'] = '1'
             Tx1, Wx1, *_ = ssq_cwt(x, _wavelet(dtype=dtype), **kw)
 
-        atol = 1e-12 if dtype == 'float64' else 1e-2
         adiff_Tx000 = np.abs(Tx00 - Tx0).mean()
         adiff_Wx000 = np.abs(Wx00 - Wx0).mean()
         assert np.allclose(Wx00, Wx0), (dtype, adiff_Wx000)
         assert np.allclose(Tx00, Tx0), (dtype, adiff_Tx000)
+
         if CAN_GPU:
+            gpu_atol = 1e-12 if dtype == 'float64' else 1e-2
             adiff_Tx01  = np.abs(Tx0 - Tx1).mean()
             adiff_Wx01  = np.abs(Wx0 - Wx1).mean()
-            assert np.allclose(Wx0, Wx1, atol=atol), (dtype, adiff_Wx01)
-            assert np.allclose(Tx0, Tx1, atol=atol), (dtype, adiff_Tx01)
+            assert np.allclose(Wx0, Wx1, atol=gpu_atol), (dtype, adiff_Wx01)
+            assert np.allclose(Tx0, Tx1, atol=gpu_atol), (dtype, adiff_Tx01)
 
             # didn't investigate float32, and `allclose` threshold is pretty bad,
             # so check MAE
@@ -617,16 +618,17 @@ def test_ssq_stft_batched():
             os.environ['SSQ_GPU'] = '1'
             Tx1, Sx1, *_ = ssq_stft(x, **kw)
 
-        atol = 1e-12 if dtype == 'float64' else 1e-6
         adiff_Tx000 = np.abs(Tx00 - Tx0).mean()
         adiff_Sx000 = np.abs(Sx00 - Sx0).mean()
         assert np.allclose(Sx00, Sx0), (dtype, adiff_Sx000)
         assert np.allclose(Tx00, Tx0), (dtype, adiff_Tx000)
+
         if CAN_GPU:
-            adiff_Tx01  = np.abs(Tx0 - Tx1)
-            adiff_Sx01  = np.abs(Sx0 - Sx1)
-            assert np.allclose(Sx0, Sx1, atol=atol), (dtype, adiff_Sx01)
-            assert np.allclose(Tx0, Tx1, atol=atol), (dtype, adiff_Tx01)
+            gpu_atol = 1e-12 if dtype == 'float64' else 5e-6
+            adiff_Tx01  = np.abs(Tx0 - Tx1).mean()
+            adiff_Sx01  = np.abs(Sx0 - Sx1).mean()
+            assert np.allclose(Sx0, Sx1, atol=gpu_atol), (dtype, adiff_Sx01)
+            assert np.allclose(Tx0, Tx1, atol=gpu_atol), (dtype, adiff_Tx01)
 
 
 def test_cwt_batched_for_loop():
diff --git a/tests/z_all_test.py b/tests/z_all_test.py
index f6d1915..5d86db4 100644
--- a/tests/z_all_test.py
+++ b/tests/z_all_test.py
@@ -32,7 +32,7 @@ def wrap(fn):
 
 #### Ensure cached imports reloaded ##########################################
 from types import ModuleType
-from imp import reload
+from importlib import reload
 import ssqueezepy