diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 9fb50a6e7..464f67f80 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -8,7 +8,7 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         arch: [linux/386, linux/amd64, linux/arm/v6, linux/arm/v7, linux/arm64, linux/ppc64le]
@@ -28,12 +28,12 @@ jobs:
       - name: Update archives
         run: sudo apt-get update
       - name: Install build tools
-        run: sudo apt-get install make git zlib1g-dev libssl-dev gperf php cmake clang-10 libc++-dev libc++abi-dev ccache
+        run: sudo apt-get install make git zlib1g-dev libssl-dev gperf php cmake clang-6.0 libc++-dev libc++abi-dev ccache
       - name: Build
         run: |
           mkdir build
           cd build
-          CXXFLAGS="-stdlib=libc++" CC=/usr/bin/clang-10 CXX=/usr/bin/clang++-10 cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX:PATH=../tdlib ..
+          CXXFLAGS="-stdlib=libc++" CC=/usr/bin/clang-6.0 CXX=/usr/bin/clang++-6.0 cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX:PATH=../tdlib ..
           cmake --build . --target install -- -j4
       - uses: actions/upload-artifact@v2
         with:
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 91e22933e..000000000
--- a/.travis.yml
+++ /dev/null
@@ -1,60 +0,0 @@
-sudo: false
-dist: trusty
-
-addons_shortcuts:
-  addons_clang38: &clang38
-    apt:
-      sources:  [ 'ubuntu-toolchain-r-test', 'llvm-toolchain-precise-3.8' ]
-      packages: [ 'g++-5', 'clang-3.8','libc++-dev', 'libc++abi-dev', 'gperf']
-  addons_gcc5: &gcc5
-    apt:
-      sources:  [ 'ubuntu-toolchain-r-test']
-      packages: [ 'gcc-5','g++-5', 'gperf']
-
-branches:
-  only:
-  - travis
-
-language: cpp
-
-matrix:
-  include:
-    - os: linux
-      env: _CXX=g++-5 _CC=gcc-5 JOBS=1
-      addons: *gcc5
-    - os: linux
-      env: _CXX=clang++-3.8 _CC=clang-3.8 JOBS=4
-      addons: *clang38
-    - os: osx
-      env: JOBS=4
-      compiler: clang
-
-before_install:
-  #- sudo apt-get -qq update
-  #- sudo apt-get install -y libxml2-dev
-
-addons:
-  apt:
-    packages:
-      - gperf
-
-
-install:
-  # /usr/bin/gcc is 4.6 always, but gcc-X.Y is available.
-  - if [ "$TRAVIS_OS_NAME" = "osx" ]; then
-      export OPENSSL_ROOT_DIR=/usr/local/opt/openssl/;
-      brew link --force readline;
-      ulimit -n 1000;
-    fi
-  - false || [ -z "$_CXX" ] || export CXX=${_CXX}
-  - false || [ -z "$_CC" ] || export CC=${_CC}
-  - echo ${PATH}
-  - echo ${CXX}
-  - ${CXX} --version
-  - ${CXX} -v
-
-script:
-  - mkdir build
-  - cd build
-  - cmake .. && make -j${JOBS} VERBOSE=1
-  - ./test/run_all_tests --filter -client