diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index d91e047ed..1c0ccb1a7 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -46,7 +46,7 @@ jobs:
           mkdir build
           cd build
           cmake -DRMG_BUILD_EXAMPLES=1 -DBUILD_TESTING=ON -DRMG_BUILD_DOCS=OFF .. | tee -a build.log
-          make | tee -a build.log
+          make -j$(nproc) | tee -a build.log
           make install | tee -a build.log
 
       - name: check version equality
@@ -87,7 +87,8 @@ jobs:
           DISPLAY: :99
         run: |
           cd build
-          ctest --output-on-failure
+          ctest --label-exclude mt -j$(nproc) --output-on-failure
+          ctest --label-regex mt -j1 --output-on-failure
 
       - name: Upload test suite outputs to GitHub
         if: ${{ always() && matrix.container_version != 'slim' }}
@@ -103,7 +104,8 @@ jobs:
           DISPLAY: :99
         run: |
           cd build
-          ctest --output-on-failure --label-exclude 'extra|vis'
+          ctest --label-exclude 'extra|vis|mt' -j$(nproc) --output-on-failure
+          ctest --label-regex mt --label-exclude 'extra|vis' -j --output-on-failure
 
       - name: Test docs building
         if: ${{ matrix.container_version != 'slim' }}
@@ -165,13 +167,14 @@ jobs:
           mkdir build
           cd build
           cmake -DCMAKE_INSTALL_PREFIX=../local -DRMG_BUILD_EXAMPLES=1 -DBUILD_TESTING=ON -DRMG_BUILD_DOCS=OFF ..
-          make
+          make -j$(nproc)
           make install
 
       - name: Run full test suite
         run: |
           cd build
-          ctest --output-on-failure
+          ctest --label-exclude mt -j$(nproc) --output-on-failure
+          ctest --label-regex mt -j1 --output-on-failure
 
       - name: Minimally test installed executable
         run: |
diff --git a/tests/confinement/CMakeLists.txt b/tests/confinement/CMakeLists.txt
index e76f4314e..2ab612db3 100644
--- a/tests/confinement/CMakeLists.txt
+++ b/tests/confinement/CMakeLists.txt
@@ -1,3 +1,6 @@
+include(ProcessorCount)
+ProcessorCount(NUM_CORES)
+
 # collect auxiliary files
 file(
   GLOB _aux
@@ -22,9 +25,9 @@ foreach(_mac ${_macros})
   add_test(NAME confinement/${_mac} COMMAND ${REMAGE_PYEXE} -g gdml/geometry.gdml -o test-out.root
                                             -- macros/${_mac})
 
-  add_test(NAME confinement-mt/${_mac} COMMAND ${REMAGE_PYEXE} -g gdml/geometry.gdml -t 2 -o
-                                               test-out.root -- macros/${_mac})
-  set_tests_properties(confinement-mt/${_mac} PROPERTIES LABELS mt)
+  add_test(NAME confinement-mt/${_mac} COMMAND ${REMAGE_PYEXE} -g gdml/geometry.gdml -t
+                                               ${NUM_CORES} -o test-out.root -- macros/${_mac})
+  set_tests_properties(confinement-mt/${_mac} PROPERTIES LABELS mt PROCESSORS ${NUM_CORES})
 
   add_test(NAME confinement-vis/${_mac}
            COMMAND ${REMAGE_PYEXE} -g gdml/geometry.gdml -o test-out.root -- macros/_vis.mac
diff --git a/tests/hades/CMakeLists.txt b/tests/hades/CMakeLists.txt
index 8ef45b0f8..9db834409 100644
--- a/tests/hades/CMakeLists.txt
+++ b/tests/hades/CMakeLists.txt
@@ -1,3 +1,6 @@
+include(ProcessorCount)
+ProcessorCount(NUM_CORES)
+
 # collect auxiliary files
 file(
   GLOB _aux
@@ -18,8 +21,9 @@ foreach(_mac ${_macros} ${_macros_extra} ${_macros_vis})
 endforeach()
 
 foreach(_mac ${_macros})
-  add_test(NAME hades-mt/${_mac} COMMAND ${REMAGE_PYEXE} -g gdml/main.gdml -t 2 macros/${_mac})
-  set_tests_properties(hades-mt/${_mac} PROPERTIES LABELS mt)
+  add_test(NAME hades-mt/${_mac} COMMAND ${REMAGE_PYEXE} -g gdml/main.gdml -t ${NUM_CORES}
+                                         macros/${_mac})
+  set_tests_properties(hades-mt/${_mac} PROPERTIES LABELS mt PROCESSORS ${NUM_CORES})
 endforeach()
 
 if(NOT BxDecay0_FOUND)
@@ -29,8 +33,9 @@ endif()
 
 if(BxDecay0_THREADSAFE)
   foreach(_mac ${_macros_extra})
-    add_test(NAME hades-mt/${_mac} COMMAND ${REMAGE_PYEXE} -g gdml/main.gdml -t 2 macros/${_mac})
-    set_tests_properties(hades-mt/${_mac} PROPERTIES LABELS "mt;extra")
+    add_test(NAME hades-mt/${_mac} COMMAND ${REMAGE_PYEXE} -g gdml/main.gdml -t ${NUM_CORES}
+                                           macros/${_mac})
+    set_tests_properties(hades-mt/${_mac} PROPERTIES LABELS "mt;extra" PROCESSORS ${NUM_CORES})
   endforeach()
 endif()
 
diff --git a/tests/vertex/CMakeLists.txt b/tests/vertex/CMakeLists.txt
index 68d3edee0..d7cff989c 100644
--- a/tests/vertex/CMakeLists.txt
+++ b/tests/vertex/CMakeLists.txt
@@ -1,3 +1,6 @@
+include(ProcessorCount)
+ProcessorCount(NUM_CORES)
+
 # collect auxiliary files
 file(
   GLOB _aux
@@ -25,7 +28,7 @@ foreach(_mac ${_macros})
                                                  vertex-input-fixture)
 
   # note: only 4 threads available on GitHub actions.
-  add_test(NAME vertex-mt/${_mac} COMMAND ${PYTHONPATH} run-vtx.py ${_mac} 4)
+  add_test(NAME vertex-mt/${_mac} COMMAND ${PYTHONPATH} run-vtx.py ${_mac} ${NUM_CORES})
   set_tests_properties(vertex-mt/${_mac} PROPERTIES LABELS "mt;extra" FIXTURES_REQUIRED
-                                                    vertex-input-fixture)
+                                                    vertex-input-fixture PROCESSORS ${NUM_CORES})
 endforeach()