diff --git a/README.md b/README.md
index b566e41..1b769d0 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@ This repository contains a script that can be used to easily install a PHP exten
 
 The script will install all the required APT/APK packages; at the end of the script execution, the no-more needed packages will be removed so that the image will be much smaller.
 
-The script works both for Alpine and Debian Linux.
+Supported docker images are all the Alpine/Debian versions, except for PHP 5.5 where we only support Debian 8 (jessie) (that is, `php:5.5`, `php:5.5-apache`, `php:5.5-cli`, `php:5.5-fpm`, `php:5.5-zts`)
 
 
 ## Usage
diff --git a/data/supported-extensions b/data/supported-extensions
index 365665e..7b3610a 100644
--- a/data/supported-extensions
+++ b/data/supported-extensions
@@ -1,14 +1,14 @@
-amqp 5.6 7.0 7.1 7.2 7.3 7.4
-apcu 5.6 7.0 7.1 7.2 7.3 7.4
-bcmath 5.6 7.0 7.1 7.2 7.3 7.4
-bz2 5.6 7.0 7.1 7.2 7.3 7.4
-calendar 5.6 7.0 7.1 7.2 7.3 7.4
+amqp 5.5 5.6 7.0 7.1 7.2 7.3 7.4
+apcu 5.5 5.6 7.0 7.1 7.2 7.3 7.4
+bcmath 5.5 5.6 7.0 7.1 7.2 7.3 7.4
+bz2 5.5 5.6 7.0 7.1 7.2 7.3 7.4
+calendar 5.5 5.6 7.0 7.1 7.2 7.3 7.4
 cmark 7.0 7.1 7.2 7.3 7.4
-dba 5.6 7.0 7.1 7.2 7.3 7.4
-enchant 5.6 7.0 7.1 7.2 7.3 7.4
-exif 5.6 7.0 7.1 7.2 7.3 7.4
-gd 5.6 7.0 7.1 7.2 7.3 7.4
-gettext 5.6 7.0 7.1 7.2 7.3 7.4
+dba 5.5 5.6 7.0 7.1 7.2 7.3 7.4
+enchant 5.5 5.6 7.0 7.1 7.2 7.3 7.4
+exif 5.5 5.6 7.0 7.1 7.2 7.3 7.4
+gd 5.5 5.6 7.0 7.1 7.2 7.3 7.4
+gettext 5.5 5.6 7.0 7.1 7.2 7.3 7.4
 gmagick 5.6 7.0 7.1 7.2 7.3 7.4
 gmp 5.6 7.0 7.1 7.2 7.3 7.4
 grpc 5.6 7.0 7.1 7.2 7.3 7.4
diff --git a/install-php-extensions b/install-php-extensions
index a0ebb61..8fbb8a2 100755
--- a/install-php-extensions
+++ b/install-php-extensions
@@ -645,6 +645,7 @@ buildRequiredPackageLists() {
 			;;
 		debian)
 			DEBIAN_FRONTEND=noninteractive apt-get update -q
+			DEBIAN_FRONTEND=noninteractive apt-get upgrade -qqy
 			;;
 	esac
 	if test -n "$buildRequiredPackageLists_persistent"; then
@@ -1324,7 +1325,7 @@ mkdir -p /tmp/src
 IPE_ERRFLAG_FILE="$(mktemp -p /tmp/src)"
 PHP_MAJMIN_VERSION=$(getPHPMajorMinor)
 case "$PHP_MAJMIN_VERSION" in
-	506 | 700 | 701 | 702 | 703 | 704) ;;
+	505 | 506 | 700 | 701 | 702 | 703 | 704) ;;
 	*)
 		printf "### ERROR: Unsupported PHP version: %s.%s ###\n" $((PHP_MAJMIN_VERSION / 100)) $((PHP_MAJMIN_VERSION % 100))
 		;;
diff --git a/scripts/tests/gd.php b/scripts/tests/gd.php
index 4f73b15..f7b562b 100644
--- a/scripts/tests/gd.php
+++ b/scripts/tests/gd.php
@@ -37,11 +37,20 @@ try {
             throw new Exception("{$saveFuntion}() function is missing");
         }
         $tempFile = tempnam(sys_get_temp_dir(), 'dpei');
+        ob_start();
         if ($saveFuntion($image, $tempFile) === false) {
             throw new Exception("{$saveFuntion}() failed");
         }
-        if (!is_file($tempFile) || filesize($tempFile) < 1) {
-            throw new Exception("{$saveFuntion}() created an empty file");
+        $contents = ob_get_contents();
+        ob_end_clean();
+        if (!is_file($tempFile)) {
+            throw new Exception("{$saveFuntion}() didn't create a file");
+        }
+        if (filesize($tempFile) < 1) {
+            if ($format !== 'xbm' || PHP_VERSION_ID >= 50600 || $contents === '') {
+                throw new Exception("{$saveFuntion}() created an empty file");
+            }
+            file_put_contents($tempFile, $contents);
         }
         $image2 = $loadFuntion($tempFile);
         unlink($tempFile);
diff --git a/scripts/travisci-test-extensions b/scripts/travisci-test-extensions
index 23ea899..f2a56bf 100755
--- a/scripts/travisci-test-extensions
+++ b/scripts/travisci-test-extensions
@@ -39,6 +39,14 @@ getDockerImageName() {
 		done
 	fi
 	getDockerImageName_imageName="$(printf 'php:%s-%s-%s' "$getDockerImageName_version" "$getDockerImageName_suffix" "$DOCKER_DISTRO")"
+	case "$getDockerImageName_imageName" in
+		php:5.5-cli-jessie)
+			getDockerImageName_imageName='php:5.5-cli'
+			;;
+		php:5.5-zts-jessie)
+			getDockerImageName_imageName='php:5.5-zts'
+			;;
+	esac
 	if test -z "$(docker images -q "$getDockerImageName_imageName" 2>/dev/null)"; then
 		getDockerImageName_log="$(docker pull "$getDockerImageName_imageName" 2>&1 || true)"
 		if test -z "$(docker images -q "$getDockerImageName_imageName" 2>/dev/null)"; then