diff --git a/.github/workflows/tests-mongodb.yml b/.github/workflows/tests-mongodb.yml
index d8df373..fa44adf 100644
--- a/.github/workflows/tests-mongodb.yml
+++ b/.github/workflows/tests-mongodb.yml
@@ -18,6 +18,14 @@ jobs:
           - "7.3"
           - "7.4"
         include:
+          - php: "5.3"
+            phpunit: "4"
+          - php: "5.4"
+            phpunit: "4"
+          - php: "5.5"
+            phpunit: "4"
+          - php: "5.6"
+            phpunit: "4"
           - php: "7.0"
             phpunit: "6"
 
@@ -39,14 +47,15 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
-          extensions: xdebug, xhprof, mongodb, tideways_xhprof
+          extensions: xdebug, xhprof, mongo, mongodb, tideways_xhprof
 
       - name: Validate composer.json and composer.lock
         run: composer validate
 
       - name: Install dependencies
         run: |
-          composer install --prefer-dist --no-progress
+          composer remove alcaeus/mongo-php-adapter --no-update --dev
+          composer install --prefer-dist
           composer require --dev phpunit/phpunit:^$PHPUNIT_VERSION
 
       - name: Install extensions
diff --git a/install-extensions.sh b/install-extensions.sh
index 9094699..951182e 100755
--- a/install-extensions.sh
+++ b/install-extensions.sh
@@ -17,14 +17,21 @@ has_extension() {
 }
 
 install_xhprof() {
-    local version="${1:-stable}"
+    local ext="xhprof" version="${1:-stable}"
 
-    has_extension "xhprof" && return 0
-    pecl install xhprof-$version
+    has_extension "$ext" && return 0
+    # https://github.com/shivammathur/setup-php/issues/905
+    sudo rm -rf /tmp/pear # shivammathur's leftovers...
+    # Allow installing to /usr/local/php
+    sudo chown -R "$(id -un):" /usr/local/php/
+    pecl install "$ext-$version"
 }
 
 install_mongo() {
-    echo no | pecl install mongo
+    local ext="mongo" version="${1:-stable}"
+
+    has_extension "$ext" && return 0
+    echo no | pecl install "$ext-$version"
 }
 
 install_mongodb() {
@@ -58,13 +65,13 @@ install_tideways_xhprof() {
 	has_extension "$extension"
 }
 
-# Show php config paths
-php --ini
+pecl version
+php -m
 
 case "$(uname -s):$PHP_VERSION" in
 *:5.*)
 	install_xhprof 0.9.4
-	install_mongo
+	install_mongo 1.6.16
 	;;
 Linux:7.*|Linux:8.*)
 	install_xhprof