diff --git a/.github/workflows/otci.yml b/.github/workflows/otci.yml
index 16c1d1eaa..d915d11a8 100644
--- a/.github/workflows/otci.yml
+++ b/.github/workflows/otci.yml
@@ -65,7 +65,7 @@ jobs:
     - name: Bootstrap
       run: |
         sudo rm /etc/apt/sources.list.d/* && sudo apt-get update
-        sudo apt-get --no-install-recommends install -y g++-multilib ninja-build python3-setuptools python3-wheel
+        sudo apt-get --no-install-recommends install -y ninja-build python3-setuptools python3-wheel
         python3 -m pip install -r tests/scripts/thread-cert/requirements.txt
         python3 -m pip install pytype adb-shell
     - name: Style check
diff --git a/.github/workflows/otns.yml b/.github/workflows/otns.yml
index 9a06645e1..fb9122d63 100644
--- a/.github/workflows/otns.yml
+++ b/.github/workflows/otns.yml
@@ -73,7 +73,7 @@ jobs:
     - name: Bootstrap
       run: |
         sudo rm /etc/apt/sources.list.d/* && sudo apt-get update
-        sudo apt-get --no-install-recommends install -y g++-multilib lcov ninja-build
+        sudo apt-get --no-install-recommends install -y lcov ninja-build
     - name: Run
       run: |
         export OT_DIR=$PWD
@@ -113,7 +113,7 @@ jobs:
       - name: Bootstrap
         run: |
           sudo rm /etc/apt/sources.list.d/* && sudo apt-get update
-          sudo apt-get --no-install-recommends install -y g++-multilib lcov ninja-build
+          sudo apt-get --no-install-recommends install -y lcov ninja-build
       - name: Run
         run: |
           export OT_DIR=$PWD
@@ -175,7 +175,7 @@ jobs:
       - name: Bootstrap
         run: |
           sudo rm /etc/apt/sources.list.d/* && sudo apt-get update
-          sudo apt-get --no-install-recommends install -y g++-multilib lcov ninja-build
+          sudo apt-get --no-install-recommends install -y lcov ninja-build
       - name: Run
         run: |
           export OT_DIR=$PWD
diff --git a/.github/workflows/simulation-1.1.yml b/.github/workflows/simulation-1.1.yml
index fe4767ed6..495920b68 100644
--- a/.github/workflows/simulation-1.1.yml
+++ b/.github/workflows/simulation-1.1.yml
@@ -65,7 +65,7 @@ jobs:
     - name: Bootstrap
       run: |
         sudo rm /etc/apt/sources.list.d/* && sudo apt-get update
-        sudo apt-get --no-install-recommends install -y g++-multilib python3-setuptools python3-wheel ninja-build lcov
+        sudo apt-get --no-install-recommends install -y python3-setuptools python3-wheel ninja-build lcov
         python3 -m pip install -r tests/scripts/thread-cert/requirements.txt
     - name: Build
       run: |
diff --git a/.github/workflows/simulation-1.4.yml b/.github/workflows/simulation-1.4.yml
index 99816e651..9e90a897f 100644
--- a/.github/workflows/simulation-1.4.yml
+++ b/.github/workflows/simulation-1.4.yml
@@ -138,7 +138,7 @@ jobs:
     - name: Bootstrap
       run: |
         sudo rm /etc/apt/sources.list.d/* && sudo apt-get update
-        sudo apt-get --no-install-recommends install -y g++-multilib python3-setuptools python3-wheel ninja-build lcov
+        sudo apt-get --no-install-recommends install -y python3-setuptools python3-wheel ninja-build lcov
         python3 -m pip install -r tests/scripts/thread-cert/requirements.txt
     - name: Build
       run: |
@@ -209,7 +209,7 @@ jobs:
     - name: Bootstrap
       run: |
         sudo rm /etc/apt/sources.list.d/* && sudo apt-get update
-        sudo apt-get --no-install-recommends install -y g++-multilib python3-setuptools python3-wheel ninja-build lcov
+        sudo apt-get --no-install-recommends install -y python3-setuptools python3-wheel ninja-build lcov
         python3 -m pip install -r tests/scripts/thread-cert/requirements.txt
     - name: Build
       run: |
@@ -348,7 +348,7 @@ jobs:
     - name: Bootstrap
       run: |
         sudo rm /etc/apt/sources.list.d/* && sudo apt-get update
-        sudo apt-get --no-install-recommends install -y libreadline6-dev g++-multilib ninja-build python3-setuptools python3-wheel llvm lcov
+        sudo apt-get --no-install-recommends install -y libreadline6-dev ninja-build python3-setuptools python3-wheel llvm lcov
         python3 -m pip install -r tests/scripts/thread-cert/requirements.txt
     - name: Build
       run: |