diff --git a/.github/workflows/php_ci.yml b/.github/workflows/php_ci.yml
index 5d0ca54..7641938 100644
--- a/.github/workflows/php_ci.yml
+++ b/.github/workflows/php_ci.yml
@@ -14,7 +14,7 @@ jobs:
 
     strategy:
       matrix:
-        php: [7.3, 7.4, 8.0, 8.1, 8.2]
+        php: [7.4, 8.0, 8.1, 8.2]
 
     steps:
       - name: Checkout
@@ -34,3 +34,15 @@ jobs:
 
       - name: PHP tests
         run: ./vendor/bin/phpunit --process-isolation tests
+
+      - name: Composer install example
+        working-directory: example
+        run: composer install
+
+      - name: Inject dummy example config
+        working-directory: example
+        run: printf "[duo]\nclient_id=DIAAAAAAAAAAAAAAAAAA\nclient_secret=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\napi_hostname=example.duosecurity.com\nredirect_uri=http://localhost:8080\nfailmode=closed\n" > ./duo.conf
+
+      - name: Ensure example runs
+        working-directory: example
+        run: php index.php
diff --git a/README.md b/README.md
index 067ac95..6223505 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ What's included:
 * `tests` - Test cases
 
 ## Getting started
-This library requires PHP 7.3 or later
+This library requires PHP 7.4 or later
 
 To use SDK in your existing developing environment, install it from Packagist
 ```
diff --git a/composer.json b/composer.json
index 9cd0734..b5e76bb 100644
--- a/composer.json
+++ b/composer.json
@@ -17,7 +17,7 @@
         }
     },
     "require": {
-        "php": ">=7.3",
+        "php": ">=7.4",
         "ext-curl": "*",
         "ext-json": "*",
         "firebase/php-jwt": "^6.0"
diff --git a/example/composer.json b/example/composer.json
index e262db7..9c3ddb1 100644
--- a/example/composer.json
+++ b/example/composer.json
@@ -1,9 +1,9 @@
 {
   "require": {
-    "slim/slim": "4.7.1",
-    "slim/psr7": "1.3.0",
-    "slim/php-view": "3.0.0",
-    "bryanjhv/slim-session": "4.0",
+    "slim/slim": "4.12.0",
+    "slim/psr7": "1.6.1",
+    "slim/php-view": "3.2.0",
+    "bryanjhv/slim-session": "4.1.2",
     "duosecurity/duo_universal_php": "@dev"
   },
   "repositories": [
diff --git a/example/dockerfile b/example/dockerfile
index 4b63b6c..49cec4a 100644
--- a/example/dockerfile
+++ b/example/dockerfile
@@ -1,9 +1,11 @@
-FROM php:7
+FROM php:8
 EXPOSE 8080
 RUN apt update && apt install -y unzip wget
 WORKDIR /root
 RUN wget https://raw.githubusercontent.com/composer/getcomposer.org/885ece8a6e1370b204b89b7a542169d25aa21177/web/installer -O - -q | php -- --quiet
-ADD . /src
+
+ADD ./composer.json /src/composer.json
 WORKDIR /src
 RUN /root/composer.phar update
+ADD . /src
 ENTRYPOINT ["php", "-S", "0.0.0.0:8080"]
diff --git a/example/index.php b/example/index.php
index f8d4465..fcd0e36 100644
--- a/example/index.php
+++ b/example/index.php
@@ -21,7 +21,7 @@
         $config['api_hostname'],
         $config['redirect_uri'],
         true,
-        $config['http_proxy'],
+        $config['http_proxy'] ?? null,
     );
 } catch (DuoException $e) {
     throw new ErrorException("*** Duo config error. Verify the values in duo.conf are correct ***\n" . $e->getMessage());