diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..a7bb1f8
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,40 @@
+---
+name: Build
+on: [pull_request]
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        compiler: [gcc, clang]
+        dynamic: [0, 1]
+        nginx:
+          # Mainline
+          - 1.21.3
+          # Stable.
+          - 1.20.1
+          # First version with loadable module support.
+          - 1.9.15
+          # Oldest supported version.
+          - 0.8.55
+        exclude:
+          - nginx: 0.8.55
+            dynamic: 1
+    runs-on: ubuntu-18.04
+    env:
+      CFLAGS: "-Wno-error"
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Install Packages
+        run: |
+          sudo apt update
+          sudo apt install -y libpcre3-dev libssl-dev
+          t/get-pup || echo 'Tests needing pup will be skipped'
+      - name: Test
+        env:
+          CC: ${{ matrix.compiler }}
+        run: |
+          CC=${{ matrix.compiler }}
+          t/build-and-run ${{ matrix.nginx }} ${{ matrix.dynamic }}
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 7953076..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,38 +0,0 @@
-language: c
-
-compiler:
-  - clang
-  - gcc
-
-env:
-  # Mainline.
-  - NGINX=1.19.7
-  - NGINX=1.19.7  DYNAMIC=1
-  # Stable.
-  - NGINX=1.18.0
-  - NGINX=1.18.0  DYNAMIC=1
-  # Other configurations.
-  - NGINX=1.12.2
-  - NGINX=1.12.2  DYNAMIC=1
-  - NGINX=1.10.3
-  # Version 1.9.15 was the first with loadable module support.
-  - NGINX=1.9.15
-  - NGINX=1.9.15  DYNAMIC=1
-  - NGINX=1.8.1
-  # Also, the oldest supported version
-  - NGINX=0.8.55
-
-sudo: false
-
-addons:
-  apt:
-    packages:
-      - libpcre3-dev
-      - libssl-dev
-
-cache: ccache
-
-script:
-  - echo "NGINX=${NGINX} ${DYNAMIC:+DYNAMIC=${DYNAMIC}}"
-  - t/get-pup || echo 'Tests needing pup will be skipped'
-  - t/build-and-run ${NGINX} ${DYNAMIC}
diff --git a/t/preamble b/t/preamble
index d3e4e30..26f2819 100644
--- a/t/preamble
+++ b/t/preamble
@@ -20,7 +20,7 @@ function nginx_conf_generate () {
 		keepalive_timeout 65;
 		server {
 			server_name localhost;
-			listen 127.0.0.1:8888;
+			listen 127.0.0.1:${NGINX_PORT};
 			root ${TESTDIR};
 			error_page 500 502 503 504 /50x.html;
 			location = /50x.html { root html; }
@@ -36,6 +36,11 @@ function nginx_conf_generate () {
 
 readonly NGINX_CONF="${PREFIX}/conf/nginx.conf"
 readonly NGINX_PID="${PREFIX}/logs/nginx.pid"
+
+NGINX_PORT=$(ss -4Htnl | awk '{ sub("[^:]+:", "", $4) ; seen[$4]=1 }
+END { p=1025 ; while (seen[p]) p++; print p}')
+readonly NGINX_PORT
+
 rm -f "${NGINX_CONF}" "${NGINX_PID}"
 mkdir -p "${PREFIX}/logs"
 
@@ -85,7 +90,7 @@ function fetch () {
 		opts+=( -S )
 		shift
 	fi
-	wget "${opts[@]}" -O- "http://localhost:8888${1:-/}" 2>&1
+	wget "${opts[@]}" -O- "http://localhost:${NGINX_PORT}${1:-/}" 2>&1
 }
 
 function skip () {