diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
new file mode 100644
index 0000000..3717cec
--- /dev/null
+++ b/.github/workflows/tests.yml
@@ -0,0 +1,147 @@
+name: Tests
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+  schedule:
+    - cron: '37 13 * * 0'
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        ruby:
+          # - 3.0
+          - 2.7
+          - 2.6
+
+    env:
+      EXPECTED_GPG_VERSION: "2.3"
+      GPG_VERSION: "latest"
+      RNP_VERSION: "v0.11.0"
+
+    steps:
+      - name: Set up environment
+        run: |
+
+          # To install and cache our dependencies we need an absolute path
+          # that does not change, is writable, and resides within
+          # GITHUB_WORKSPACE.
+          # On macOS GITHUB_WORKSPACE includes the github runner version,
+          # so it does not remain constant.
+          # This causes problems with, for example, pkgconfig files
+          # referencing paths that no longer exist.
+          export DEPS_BUILD_DIR="${{ github.workspace }}/build"
+          export DEPS_PREFIX="${{ github.workspace }}/opt"
+          export CACHE_DIR="${DEPS_PREFIX}"
+          export BOTAN_PREFIX="${DEPS_PREFIX}/botan"
+          export JSONC_PREFIX="${DEPS_PREFIX}/json-c"
+          export RNP_PREFIX="${DEPS_PREFIX}/rnp"
+          export GPG_PREFIX="${DEPS_PREFIX}/gpg"
+          export PATH="${RNP_PREFIX}/bin:${GPG_PREFIX}/bin:${PATH}"
+
+          # Many of these are supported only in few GPG components, hence bunch of
+          # harmless warnings typically shows up.
+          export GPG_CONFIGURE_OPTS="
+            --disable-doc \
+            --enable-pinentry-curses \
+            --disable-pinentry-emacs \
+            --disable-pinentry-gtk2 \
+            --disable-pinentry-gnome3 \
+            --disable-pinentry-qt \
+            --disable-pinentry-qt4 \
+            --disable-pinentry-qt5 \
+            --disable-pinentry-tqt \
+            --disable-pinentry-fltk \
+            --prefix=${GPG_PREFIX} \
+            --with-libgpg-error-prefix=${GPG_PREFIX} \
+            --with-libassuan-prefix=${GPG_PREFIX} \
+            --with-libgpg-error-prefix=${GPG_PREFIX} \
+            --with-libgcrypt-prefix=${GPG_PREFIX} \
+            --with-libassuan-prefix=${GPG_PREFIX} \
+            --with-ksba-prefix=${GPG_PREFIX} \
+            --with-npth-prefix=${GPG_PREFIX}"
+
+
+          # Be aware of differences between LD_LIBRARY_PATH and LD_RUN_PATH.
+          # - http://osr507doc.sco.com/en/tools/ccs_linkedit_dynamic_dirsearch.html
+          # - https://www.hpc.dtu.dk/?page_id=1180
+          #
+          # You should be careful when attempting to replicate following in your
+          # setup, because setting LD_LIBRARY_PATH is often a bad idea.  Nevertheless,
+          # it is okay here in Travis, and actually any attempt to change these led me
+          # to linking failures.  Side note: I am not a Linux expert, and you may be
+          # more lucky.
+          #
+          # I'd be happy to get rid of LD_LIBRARY_PATH eventually in some future
+          # pull request.
+          export LD_LIBRARY_PATH="${BOTAN_PREFIX}/lib:${JSONC_PREFIX}/lib:${RNP_PREFIX}/lib"
+          export LD_RUN_PATH="${GPG_PREFIX}/lib"
+
+          for i in \
+            CACHE_DIR \
+            DEPS_BUILD_DIR \
+            DEPS_PREFIX \
+            BOTAN_PREFIX \
+            JSONC_PREFIX \
+            RNP_PREFIX \
+            GPG_PREFIX \
+            PATH \
+            LD_LIBRARY_PATH \
+            LD_RUN_PATH \
+          ; do \
+            echo "${i}=${!i}" >> $GITHUB_ENV; \
+          done
+
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 1
+          submodules: true
+
+      - name: Prepare cache key
+        run: |
+          echo "YEAR_MONTH=$(date +%Y%m)" >> "${GITHUB_ENV}"
+
+      - name: Cache
+        id: cache
+        uses: actions/cache@v2
+        with:
+          path: ${{ env.CACHE_DIR }}
+          key: ${{ github.workflow }}-${{ runner.os }}-${{ env.RNP_VERSION }}-${{ env.GPG_VERSION }}-gpg-${{ env.EXPECTED_GPG_VERSION }}-${{ hashFiles('ci/**') }}-${{ hashFiles('.github/workflows/**') }}-${{ env.YEAR_MONTH }}
+
+      - name: Build cache
+        if: steps.cache.outputs.cache-hit != 'true'
+        run: |
+          mkdir -p "${DEPS_PREFIX}"
+          pushd ci/gpg
+          ./install_gpg_all.sh \
+            --suite-version "${GPG_VERSION}" \
+            --build-dir "${DEPS_BUILD_DIR}/gpg" \
+            --sudo --ldconfig \
+            --configure-opts "${GPG_CONFIGURE_OPTS}"
+          popd
+          pushd ci
+          ./install_botan.sh
+          ./install_json_c.sh
+          ./install_rnp.sh
+          popd
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler-cache: true # runs 'bundle install' and caches installed gems automatically
+        env:
+          --env: ImageOS=ubuntu18
+
+      - name: Before script
+        run: |
+          bundle exec rake pgp_keys:generate
+          bundle exec rake pgp_keys:list
+
+      - name: Run tests
+        run: bundle exec rspec --format documentation --profile 200
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 79e283b..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,94 +0,0 @@
-dist: xenial
-sudo: required
-language: ruby
-
-rvm:
-  - 2.6
-  - 2.5
-  - 2.4
-  - 2.3
-  - ruby-head
-
-env:
-  global:
-    - EXPECT_GPG_VERSION="2.2"
-    - GPG_VERSION="latest"
-    - RNP_VERSION="master"
-
-    - DEPS_BUILD_DIR="${TRAVIS_BUILD_DIR}/build"
-    - DEPS_PREFIX="${TRAVIS_BUILD_DIR}/opt"
-    - BOTAN_PREFIX="${DEPS_PREFIX}/botan"
-    - JSONC_PREFIX="${DEPS_PREFIX}/json-c"
-    - RNP_PREFIX="${DEPS_PREFIX}/rnp"
-    - GPG_PREFIX="${DEPS_PREFIX}/gpg"
-
-    # Be aware of differences between LD_LIBRARY_PATH and LD_RUN_PATH.
-    # - http://osr507doc.sco.com/en/tools/ccs_linkedit_dynamic_dirsearch.html
-    # - https://www.hpc.dtu.dk/?page_id=1180
-    #
-    # You should be careful when attempting to replicate following in your
-    # setup, because setting LD_LIBRARY_PATH is often a bad idea.  Nevertheless,
-    # it is okay here in Travis, and actually any attempt to change these led me
-    # to linking failures.  Side note: I am not a Linux expert, and you may be
-    # more lucky.
-    #
-    # I'd be happy to get rid of LD_LIBRARY_PATH eventually in some future
-    # pull request.
-    - LD_LIBRARY_PATH="${BOTAN_PREFIX}/lib:${JSONC_PREFIX}/lib:${RNP_PREFIX}/lib"
-    - LD_RUN_PATH="${GPG_PREFIX}/lib"
-
-    - PATH="${RNP_PREFIX}/bin:${GPG_PREFIX}/bin:${PATH}"
-
-    # Many of these are supported only in few GPG components, hence bunch of
-    # harmless warnings typically shows up.
-    - >
-      GPG_CONFIGURE_OPTS="--disable-doc --enable-pinentry-curses
-      --disable-pinentry-emacs --disable-pinentry-gtk2 --disable-pinentry-gnome3
-      --disable-pinentry-qt --disable-pinentry-qt4 --disable-pinentry-qt5
-      --disable-pinentry-tqt --disable-pinentry-fltk
-      --prefix=${GPG_PREFIX}
-      --with-libgpg-error-prefix=${GPG_PREFIX}
-      --with-libassuan-prefix=${GPG_PREFIX}
-      --with-libgpg-error-prefix=${GPG_PREFIX}
-      --with-libgcrypt-prefix=${GPG_PREFIX}
-      --with-libassuan-prefix=${GPG_PREFIX}
-      --with-ksba-prefix=${GPG_PREFIX}
-      --with-npth-prefix=${GPG_PREFIX}"
-
-before_install:
-  - mkdir -p ${DEPS_PREFIX}
-  - pushd ci/gpg
-  - >
-    ./install_gpg_all.sh
-    --suite-version "${GPG_VERSION}"
-    --build-dir "${DEPS_BUILD_DIR}/gpg"
-    --configure-opts "${GPG_CONFIGURE_OPTS}"
-    --folding-style travis
-  - popd
-  - pushd ci
-  - ./install_botan.sh
-  - ./install_json_c.sh
-  - ./install_rnp.sh
-  - popd
-  - gem install bundler -v "~> 2.0"
-
-before_script:
-  - bundle exec rake pgp_keys:generate
-  - bundle exec rake pgp_keys:list
-
-script:
-  - bundle exec rspec --format documentation --profile 200
-
-matrix:
-  include:
-    - env: TEST_WITHOUT_RNP="1"
-    - env: TEST_WITHOUT_GPGME="1"
-    # Test against older GPG versions
-    - env: GPG_VERSION="2.1" EXPECT_GPG_VERSION="2.1"
-    - gemfile: "ci/Mail-2.6.4.gemfile"
-    - gemfile: "ci/Mail-2.6.gemfile"
-    - gemfile: "ci/Mail-head.gemfile"
-
-  allow_failures:
-    - rvm: ruby-head
-    - gemfile: "ci/Mail-head.gemfile"
diff --git a/README.adoc b/README.adoc
index 56ef148..07f56e5 100644
--- a/README.adoc
+++ b/README.adoc
@@ -3,8 +3,8 @@
 ifdef::env-github[]
 image:https://img.shields.io/gem/v/enmail.svg[
 	Gem Version, link="https://rubygems.org/gems/enmail"]
-image:https://img.shields.io/travis/riboseinc/enmail/master.svg[
-	Build Status, link="https://travis-ci.com/riboseinc/enmail/branches"]
+image:https://github.com/riboseinc/enmail/actions/workflows/tests.yml/badge.svg[
+	Build Status, link="https://github.com/riboseinc/enmail/actions/workflows/tests.yml"]
 image:https://img.shields.io/codecov/c/github/riboseinc/enmail.svg[
 	Test Coverage, link="https://codecov.io/gh/riboseinc/enmail"]
 image:https://img.shields.io/codeclimate/maintainability/riboseinc/enmail.svg[
diff --git a/ci/botan-modules b/ci/botan-modules
new file mode 100644
index 0000000..626e0fe
--- /dev/null
+++ b/ci/botan-modules
@@ -0,0 +1,45 @@
+aead
+aes
+auto_rng
+bigint
+blowfish
+camellia
+cast128
+cbc
+cfb
+crc24
+curve25519
+des
+dl_algo
+dl_group
+dsa
+eax
+ecc_key
+ecdh
+ecdsa
+ed25519
+elgamal
+eme_pkcs1
+emsa_pkcs1
+emsa_raw
+ffi
+hash
+hmac
+hmac_drbg
+idea
+kdf
+md5
+ocb
+pgp_s2k
+rfc3394
+rmd160
+rsa
+sha1
+sha2_32
+sha2_64
+sha3
+sm2
+sm3
+sm4
+sp800_56a
+twofish
diff --git a/ci/install_botan.sh b/ci/install_botan.sh
index b3962dc..f2783b3 100755
--- a/ci/install_botan.sh
+++ b/ci/install_botan.sh
@@ -8,21 +8,35 @@
 
 set -eux
 
-: "${CORES:=2}"
+: "${MAKE_PARALLEL:=2}"
 : "${MAKE:=make}"
+: "${BOTAN_MODULES=$(<./botan-modules tr '\n' ',')}"
 
-botan_build="${DEPS_BUILD_DIR}/botan"
+# Copied from rnp:ci/lib/cacheable_install_functions.inc.sh
+install_botan() {
+	# botan
+	local botan_build=${LOCAL_BUILDS}/botan
+	if [[ ! -e "${BOTAN_INSTALL}/lib/libbotan-2.so" ]] && \
+		[[ ! -e "${BOTAN_INSTALL}/lib/libbotan-2.dylib" ]] && \
+		[[ ! -e "${BOTAN_INSTALL}/lib/libbotan-2.a" ]]; then
 
-if [ ! -e "${BOTAN_PREFIX}/lib/libbotan-2.so" ] && \
-	 [ ! -e "${BOTAN_PREFIX}/lib/libbotan-2.dylib" ]; then
-
-	if [ -d "${botan_build}" ]; then
+	if [[ -d "${botan_build}" ]]; then
 		rm -rf "${botan_build}"
 	fi
 
-	git clone --depth 1 https://github.com/randombit/botan "${botan_build}"
+	git clone --depth 1 --branch "${RECOMMENDED_BOTAN_VERSION}" https://github.com/randombit/botan "${botan_build}"
 	pushd "${botan_build}"
-	./configure.py --prefix="${BOTAN_PREFIX}" --with-debug-info --cxxflags="-fno-omit-frame-pointer"
-	${MAKE} -j${CORES} install
-	popd
-fi
+
+	./configure.py --prefix="${BOTAN_INSTALL}" --with-debug-info --cxxflags="-fno-omit-frame-pointer" \
+		--without-documentation --without-openssl --build-targets=shared \
+		--minimized-build --enable-modules="$BOTAN_MODULES"
+			${MAKE} -j"${MAKE_PARALLEL}" install
+			popd
+	fi
+}
+
+export LOCAL_BUILDS="${DEPS_BUILD_DIR}"
+export BOTAN_INSTALL="${BOTAN_PREFIX}"
+export RECOMMENDED_BOTAN_VERSION="${BOTAN_VERSION:-2.17.3}"
+
+install_botan
diff --git a/ci/install_json_c.sh b/ci/install_json_c.sh
index 49a34a9..6ee800c 100755
--- a/ci/install_json_c.sh
+++ b/ci/install_json_c.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# (c) Copyright 2018 Ribose Inc.
+# (c) Copyright 2021 Ribose Inc.
 #
 
 # Based on:
@@ -8,25 +8,36 @@
 
 set -eux
 
-: "${CORES:=2}"
+: "${MAKE_PARALLEL:=2}"
 : "${MAKE:=make}"
 
 jsonc_build="${DEPS_BUILD_DIR}/json-c"
 
-if [ ! -e "${JSONC_PREFIX}/lib/libjson-c.so" ] && \
-	 [ ! -e "${JSONC_PREFIX}/lib/libjson-c.dylib" ]; then
+# Copied from rnp:ci/lib/cacheable_install_functions.inc.sh
+install_jsonc() {
+	local jsonc_build=${LOCAL_BUILDS}/json-c
+	if [[ ! -e "${JSONC_INSTALL}/lib/libjson-c.so" ]] && \
+		[[ ! -e "${JSONC_INSTALL}/lib/libjson-c.dylib" ]] && \
+		[[ ! -e "${JSONC_INSTALL}/lib/libjson-c.a" ]]; then
 
-	 if [ -d "${jsonc_build}" ]; then
-		 rm -rf "${jsonc_build}"
-	 fi
+	if [ -d "${jsonc_build}" ]; then
+		rm -rf "${jsonc_build}"
+	fi
 
 	mkdir -p "${jsonc_build}"
-	pushd ${jsonc_build}
-	wget https://s3.amazonaws.com/json-c_releases/releases/json-c-0.12.1.tar.gz -O json-c.tar.gz
+	pushd "${jsonc_build}"
+	wget https://s3.amazonaws.com/json-c_releases/releases/json-c-"${RECOMMENDED_JSONC_VERSION}".tar.gz -O json-c.tar.gz
 	tar xzf json-c.tar.gz --strip 1
 
 	autoreconf -ivf
-	env CFLAGS="-fno-omit-frame-pointer -g" ./configure --prefix="${JSONC_PREFIX}"
-	${MAKE} -j${CORES} install
+	env CFLAGS="-fno-omit-frame-pointer -Wno-implicit-fallthrough -g" ./configure --prefix="${JSONC_INSTALL}"
+	${MAKE} -j"${MAKE_PARALLEL}" install
 	popd
-fi
+	fi
+}
+
+export LOCAL_BUILDS="${DEPS_BUILD_DIR}"
+export JSONC_INSTALL="${JSONC_PREFIX}"
+export RECOMMENDED_JSONC_VERSION="${JSONC_VERSION:-0.12.1}"
+
+install_jsonc
diff --git a/ci/install_rnp.sh b/ci/install_rnp.sh
index 7ca14de..1b2d125 100755
--- a/ci/install_rnp.sh
+++ b/ci/install_rnp.sh
@@ -13,10 +13,10 @@ set -eux
 
 rnp_build="${DEPS_BUILD_DIR}/rnp"
 
-if [ ! -e "${RNP_PREFIX}/lib/librnp.so" ] && \
-	 [ ! -e "${RNP_PREFIX}/lib/librnp.dylib" ]; then
+if [[ ! -e "${RNP_PREFIX}/lib/librnp.so" ]] && \
+	 [[ ! -e "${RNP_PREFIX}/lib/librnp.dylib" ]]; then
 
-	git clone https://github.com/riboseinc/rnp ${rnp_build}
+	git clone https://github.com/riboseinc/rnp "${rnp_build}"
 	pushd "${rnp_build}"
 	git checkout "$RNP_VERSION"
 	cmake \
diff --git a/enmail.gemspec b/enmail.gemspec
index d174cfd..e38b617 100644
--- a/enmail.gemspec
+++ b/enmail.gemspec
@@ -44,5 +44,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rake", ">= 10", "< 13"
   spec.add_development_dependency "rnp", *EnMail::DependencyConstraints::RNP
   spec.add_development_dependency "rspec", "~> 3.0"
-  spec.add_development_dependency "rspec-pgp_matchers", "~> 0.1.1"
+  spec.add_development_dependency "rspec-pgp_matchers", "~> 0.2.0"
 end
diff --git a/spec/support/expect_correct_gpg_version.rb b/spec/support/expect_correct_gpg_version.rb
index 8822d25..485582b 100644
--- a/spec/support/expect_correct_gpg_version.rb
+++ b/spec/support/expect_correct_gpg_version.rb
@@ -1,7 +1,7 @@
 # (c) Copyright 2018 Ribose Inc.
 #
 
-expected_gpg_version = ENV.fetch("EXPECT_GPG_VERSION", nil)
+expected_gpg_version = ENV.fetch("EXPECTED_GPG_VERSION", nil)
 
 if expected_gpg_version && ENV.fetch("TEST_WITHOUT_GPGME", nil).nil?
   require "gpgme"