diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 6a06554..2cd369d 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -12,13 +12,10 @@ test_arosics:
   stage: test
   coverage: '/TOTAL\s+\d+\s+\d+\s+(\d+%)/'
   script:
-    - source /opt/conda/bin/activate ci_env
+    - source activate ci_env
 
     # update py_tools_ds and geoarray
-    - pip install -U py_tools_ds -q
-    - pip install -U geoarray -q
-
-    - pip install scipy  # TODO remove as soon as CI runner is rebuilt
+    - mamba update py-tools-ds geoarray
 
     # run tests
     - make pytest
@@ -44,7 +41,7 @@ test_arosics:
 test_styles:
   stage: test
   script:
-    - source /opt/conda/bin/activate ci_env
+    - source activate ci_env
     - make lint
   artifacts:
     paths:
@@ -57,7 +54,7 @@ test_styles:
 test_urls:
   stage: test
   script:
-    - source /opt/conda/bin/activate ci_env
+    - source activate ci_env
     - pip install -U urlchecker
     - make urlcheck
   when: always
@@ -66,7 +63,7 @@ test_urls:
 test_arosics_install:
   stage: test
   script:
-    - source /opt/conda/bin/activate
+    - source activate
     - mamba update -n base mamba conda
 
     # create arosics environment from environment_arosics.yml
@@ -82,6 +79,9 @@ test_arosics_install:
     # test importability
     - python -c "import arosics; print(arosics)"
     - python -c "from arosics import COREG, COREG_LOCAL"
+
+    # check if dependencies are properly installed
+    - pip check || exit
   only:
     - main
 
@@ -128,7 +128,7 @@ deploy_pypi:
   dependencies:
     - test_arosics
   script:
-    - source /opt/conda/bin/activate ci_env
+    - source activate ci_env
     - pip install -U twine
     - python setup.py sdist
     - twine upload dist/*  # requires creds as environment variables
diff --git a/HISTORY.rst b/HISTORY.rst
index 945a590..37c4a00 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -8,6 +8,7 @@ History
 * Removed dill from requirements.
 * !37: Fixed issue #82 (IndexError: cannot do a non-empty take from an empty axes) which happened in case COREG_LOCAL
   could not find a single tie point.
+* !38: Updated CI (now faster) and environment file (now uses conda where ever possible).
 
 
 1.9.0 (2023-05-04)
diff --git a/tests/CI_docker/context/arosics_ci.docker b/tests/CI_docker/context/arosics_ci.docker
index 659ad7d..c0f72db 100644
--- a/tests/CI_docker/context/arosics_ci.docker
+++ b/tests/CI_docker/context/arosics_ci.docker
@@ -1,4 +1,4 @@
-FROM ci_base_ubuntu:0.1
+FROM ci_base_ubuntu:0.2
 
 # use bash shell instead of sh shell for all docker commands
 SHELL ["/bin/bash", "-c"]
@@ -7,10 +7,9 @@ SHELL ["/bin/bash", "-c"]
 COPY *.yml /root/
 
 # update base environment
-RUN mamba update --all -y && \
+RUN mamba update -y -n base mamba conda && \
     conda clean -afy
 
 # create ci_env environment
 RUN mamba env create -n ci_env -f /root/environment_arosics.yml && \
-    conda clean -afy && \
-    conda list
+    conda clean -afy
diff --git a/tests/CI_docker/context/environment_arosics.yml b/tests/CI_docker/context/environment_arosics.yml
index a0e66e9..4861700 100644
--- a/tests/CI_docker/context/environment_arosics.yml
+++ b/tests/CI_docker/context/environment_arosics.yml
@@ -8,14 +8,17 @@ dependencies:
   - pip
   - cartopy
   - cmocean
+  - folium>=0.6.0,!=0.12.0
   - gdal
   - geoarray>=0.15.0
+  - geojson
   - geopandas
   - holoviews
   - ipython  # needed to test interactive plotting
   - matplotlib
   - nbformat  # optional dependency of plotly, needed to test interactive plotting
   - numpy
+  - packaging
   - pandas
   - plotly
   - pyfftw  # pyfftw>=0.13.0 is currently not used due to https://github.com/pyFFTW/pyFFTW/issues/294
@@ -24,23 +27,20 @@ dependencies:
   - py-tools-ds>=0.18.0
   - scikit-image>=0.16.0
   - scikit-learn
+  - scipy
   - shapely
 
-  - pip:
-    - folium>=0.6.0,!=0.12.0
-    - geojson
-    - packaging
-    - scipy
+  # doc/lint/test requirements
+  - flake8
+  - pycodestyle
+  - pydocstyle
+  - pylint
+  - pytest
+  - pytest-cov
+  - sphinx-argparse
+  - sphinx-autodoc-typehints
+  - sphinx_rtd_theme
+  - urlchecker
 
-    # doc requirements
-    - flake8
-    - pycodestyle
-    - pydocstyle
-    - pylint
-    - pytest
-    - pytest-cov
+  - pip:
     - pytest-reporter-html1
-    - sphinx-argparse
-    - sphinx-autodoc-typehints
-    - sphinx_rtd_theme
-    - urlchecker