diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 4c9e114a55c22341be115484a2f71f303493726a..85b7c5920aacf54a18f9e421dfef3bfa03a37136 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -43,7 +43,7 @@ tests (from scratch):
   script:
     - zypper --non-interactive install binutils libproj-devel gdal-devel
     - zypper --non-interactive install proj geos-devel
-    - pip install -r requirements.txt
+    - cat requirements.txt | xargs -L 1 pip install
     - chmod +x ./CI/run_pytest.sh
     - ./CI/run_pytest.sh
   after_script:
@@ -72,7 +72,7 @@ tests (on GPU):
     - chmod +x ./CI/update_badge.sh
     - ./CI/update_badge.sh > /dev/null
   script:
-    - pip install -r requirements_gpu.txt
+    - cat requirements_gpu.txt | xargs -L 1 pip install
     - chmod +x ./CI/run_pytest.sh
     - ./CI/run_pytest.sh
   after_script:
@@ -96,7 +96,7 @@ tests:
     - chmod +x ./CI/update_badge.sh
     - ./CI/update_badge.sh > /dev/null
   script:
-    - pip install -r requirements.txt
+    - cat requirements.txt | xargs -L 1 pip install
     - chmod +x ./CI/run_pytest.sh
     - ./CI/run_pytest.sh
   after_script:
@@ -120,7 +120,7 @@ coverage:
     - chmod +x ./CI/update_badge.sh
     - ./CI/update_badge.sh > /dev/null
   script:
-    - pip install -r requirements.txt
+    - cat requirements.txt | xargs -L 1 pip install
     - chmod +x ./CI/run_pytest_coverage.sh
     - ./CI/run_pytest_coverage.sh
   after_script:
@@ -142,8 +142,8 @@ sphinx docs:
     - chmod +x ./CI/update_badge.sh
     - ./CI/update_badge.sh > /dev/null
   script:
-    - pip install -r requirements.txt
-    - pip install -r docs/requirements_docs.txt
+    - cat requirements.txt | xargs -L 1 pip install
+    - cat docs/requirements.txt | xargs -L 1 pip install
     - chmod +x ./CI/create_documentation.sh
     - ./CI/create_documentation.sh
   after_script:
diff --git a/README.md b/README.md
index 43fb50cd0cde1dbeae9eb5adbd71a5a0e95548a0..636e673aaaf589e2a4193c7731f43fd305b8a8a3 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,10 @@ HPC systems, see [here](#special-instructions-for-installation-on-jülich-hpc-sy
 * (geo) Install **proj** and **GEOS** on your machine using the console.
 * Install the **python3.6 develop** libraries.
 * Install all **requirements** from [`requirements.txt`](https://gitlab.version.fz-juelich.de/toar/mlair/-/blob/master/requirements.txt)
-  preferably in a virtual environment
+  preferably in a virtual environment. You can use `pip install -r requirements.txt` to install all requirements at 
+  once. Note, we recently updated the version of Cartopy and there seems to be an ongoing 
+  [issue](https://github.com/SciTools/cartopy/issues/1552) when installing numpy and Cartopy at the same time. If you
+  run into trouble, you could use ` cat requirements.txt | xargs -L 1 pip install` instead.
 * Installation of **MLAir**:
     * Either clone MLAir from the [gitlab repository](https://gitlab.version.fz-juelich.de/toar/mlair.git) 
       and use it without installation (beside the requirements)