diff --git a/.github/workflows/test-basic.yml b/.github/workflows/test-basic.yaml
similarity index 96%
rename from .github/workflows/test-basic.yml
rename to .github/workflows/test-basic.yaml
index 879da72..13f5967 100644
--- a/.github/workflows/test-basic.yml
+++ b/.github/workflows/test-basic.yaml
@@ -12,7 +12,7 @@ jobs:
   build:
     strategy:
       matrix:
-        os: [ubuntu-16.04, ubuntu-18.04, ubuntu-20.04, macos-latest]
+        os: [ubuntu-18.04, ubuntu-20.04, macos-latest]
         python-version: [3.6, 3.7, 3.8, 3.9]
 
     runs-on: ${{ matrix.os }}
diff --git a/.github/workflows/test-misc.yml b/.github/workflows/test-misc.yaml
similarity index 92%
rename from .github/workflows/test-misc.yml
rename to .github/workflows/test-misc.yaml
index bfea43e..1dac3a8 100644
--- a/.github/workflows/test-misc.yml
+++ b/.github/workflows/test-misc.yaml
@@ -12,7 +12,7 @@ jobs:
   build:
     strategy:
       matrix:
-        os: [ubuntu-16.04, ubuntu-18.04, ubuntu-20.04, macos-latest]
+        os: [ubuntu-18.04, ubuntu-20.04, macos-latest]
         python-version: [3.6, 3.7, 3.8, 3.9]
 
     runs-on: ${{ matrix.os }}
diff --git a/.github/workflows/test-super-layer_model.yml b/.github/workflows/test-super-layer_model.yaml
similarity index 92%
rename from .github/workflows/test-super-layer_model.yml
rename to .github/workflows/test-super-layer_model.yaml
index eef2420..87cdd6a 100644
--- a/.github/workflows/test-super-layer_model.yml
+++ b/.github/workflows/test-super-layer_model.yaml
@@ -12,7 +12,7 @@ jobs:
   build:
     strategy:
       matrix:
-        os: [ubuntu-16.04, ubuntu-18.04, ubuntu-20.04, macos-latest]
+        os: [ubuntu-18.04, ubuntu-20.04, macos-latest]
         python-version: [3.6, 3.7, 3.8, 3.9]
 
     runs-on: ${{ matrix.os }}