diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 22712c5ed56d99f137065a7592ed25d3abf7370b..a7c604cbef2c6ef672e3faa7e39758414444a5df 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -376,7 +376,7 @@ intel_19_hybrid:
    <<: *build_definition
    image: i10git.cs.fau.de:5005/walberla/buildenvs/intel:19
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_hybrid_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -393,7 +393,7 @@ intel_19_serial_dbg:
    <<: *build_definition
    image: i10git.cs.fau.de:5005/walberla/buildenvs/intel:19
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_serial_dbg_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -410,7 +410,7 @@ intel_19_mpionly_dbg:
    <<: *build_definition
    image: i10git.cs.fau.de:5005/walberla/buildenvs/intel:19
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_mpionly_dbg_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -427,7 +427,7 @@ intel_19_hybrid_dbg:
    <<: *build_definition
    image: i10git.cs.fau.de:5005/walberla/buildenvs/intel:19
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_hybrid_dbg_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -444,7 +444,7 @@ intel_19_hybrid_dbg_sp:
    <<: *build_definition
    image: i10git.cs.fau.de:5005/walberla/buildenvs/intel:19
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_hybrid_dbg_sp_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -866,7 +866,7 @@ gcc_9_hybrid:
    image: i10git.cs.fau.de:5005/walberla/buildenvs/gcc:9
    stage: pretest
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_hybrid_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -882,7 +882,7 @@ gcc_9_serial_dbg:
    <<: *build_definition
    image: i10git.cs.fau.de:5005/walberla/buildenvs/gcc:9
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_serial_dbg_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -898,7 +898,7 @@ gcc_9_mpionly_dbg:
    <<: *build_definition
    image: i10git.cs.fau.de:5005/walberla/buildenvs/gcc:9
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_mpionly_dbg_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -914,7 +914,7 @@ gcc_9_hybrid_dbg:
    <<: *build_definition
    image: i10git.cs.fau.de:5005/walberla/buildenvs/gcc:9
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_hybrid_dbg_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -930,7 +930,7 @@ gcc_9_hybrid_dbg_sp:
    <<: *build_definition
    image: i10git.cs.fau.de:5005/walberla/buildenvs/gcc:9
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_hybrid_dbg_sp_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -1434,7 +1434,7 @@ clang_9.0_hybrid:
    <<: *build_definition
    image: i10git.cs.fau.de:5005/walberla/buildenvs/clang:9.0
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_hybrid_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -1450,7 +1450,7 @@ clang_9.0_serial_dbg:
    <<: *build_definition
    image: i10git.cs.fau.de:5005/walberla/buildenvs/clang:9.0
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_serial_dbg_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -1466,7 +1466,7 @@ clang_9.0_mpionly_dbg:
    <<: *build_definition
    image: i10git.cs.fau.de:5005/walberla/buildenvs/clang:9.0
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_mpionly_dbg_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -1482,7 +1482,7 @@ clang_9.0_hybrid_dbg:
    <<: *build_definition
    image: i10git.cs.fau.de:5005/walberla/buildenvs/clang:9.0
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_hybrid_dbg_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"
@@ -1499,7 +1499,7 @@ clang_9.0_hybrid_dbg_sp:
    image: i10git.cs.fau.de:5005/walberla/buildenvs/clang:9.0
    stage: pretest
    before_script:
-      -pip3 install lbmpy-walberla --upgrade
+      - pip3 install lbmpy-walberla --upgrade
    variables:
       <<: *build_hybrid_dbg_sp_variables
       WALBERLA_BUILD_WITH_CUDA: "OFF"