diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
deleted file mode 100644
index 1020c11..0000000
--- a/.github/workflows/macos.yml
+++ /dev/null
@@ -1,22 +0,0 @@
-name: MacOS
-
-on:
-  push:
-    branches:
-      - master
-  pull_request:
-    branches:
-      - master
-
-jobs:
-  build:
-
-    runs-on: macos-latest
-    
-    steps:
-    - uses: actions/checkout@v1
-    
-    - name: run tests
-      run: |
-        cmake -Htest -Bbuild/test
-        cmake --build build/test --target test-verbose
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..c7b90cd
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,25 @@
+name: Test
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  tests:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+
+    steps:
+      - name: clone
+        uses: actions/checkout@v2
+
+      - name: unit tests
+        run: |
+          cmake -Htest -Bbuild/test
+          cmake --build build/test --target test-verbose
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
deleted file mode 100644
index cca9b9a..0000000
--- a/.github/workflows/ubuntu.yml
+++ /dev/null
@@ -1,29 +0,0 @@
-name: Ubuntu
-
-on:
-  push:
-    branches:
-    - master
-  pull_request:
-    branches:
-    - master
-
-jobs:
-  build:
-
-    runs-on: ubuntu-latest
-    
-    steps:
-    - uses: actions/checkout@v1
-    
-    - name: install updates
-      run: |
-        wget -O cmake.sh https://cmake.org/files/v3.14/cmake-3.14.0-Linux-x86_64.sh 
-        sudo sh cmake.sh --skip-license --exclude-subdir --prefix=/usr/local
-        export PATH=/usr/local/bin:$PATH
-        cmake --version
-    
-    - name: run tests
-      run: |
-        cmake -Htest -Bbuild/test
-        cmake --build build/test --target test-verbose
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
deleted file mode 100644
index 165a67f..0000000
--- a/.github/workflows/windows.yml
+++ /dev/null
@@ -1,22 +0,0 @@
-name: Windows
-
-on:
-  push:
-    branches:
-    - master
-  pull_request:
-    branches:
-    - master
-
-jobs:
-  build:
-
-    runs-on: windows-latest
-    
-    steps:
-    - uses: actions/checkout@v1
-    
-    - name: run tests
-      run: |
-        cmake -Htest -Bbuild/test
-        cmake --build build/test --target test-verbose