diff --git a/install-php-extensions b/install-php-extensions
index 813be75..ba16d4e 100755
--- a/install-php-extensions
+++ b/install-php-extensions
@@ -180,10 +180,6 @@ sortModulesToInstall() {
 # Set:
 #   PACKAGES_PERSISTENT
 #   PACKAGES_VOLATILE
-#
-# Return:
-#   0 (true): if we to install some package
-#   1 (false): if no package is required
 buildRequiredPackageLists() {
 	buildRequiredPackageLists_persistent=''
 	buildRequiredPackageLists_volatile=''
@@ -202,7 +198,7 @@ buildRequiredPackageLists() {
 			fi
 			;;
 		debian@9)
-			buildRequiredPackageLists_libssldev='libssl-dev'
+			buildRequiredPackageLists_libssldev='libssl1.0-dev'
 			;;
 		debian@*)
 			buildRequiredPackageLists_libssldev='libssl([0-9]+(\.[0-9]+)*)?-dev$'
@@ -555,7 +551,7 @@ buildRequiredPackageLists() {
 	PACKAGES_PERSISTENT=''
 	PACKAGES_VOLATILE=''
 	if test -z "$buildRequiredPackageLists_persistent$buildRequiredPackageLists_volatile"; then
-		return 0
+		return
 	fi
 	case "$buildRequiredPackageLists_distro" in
 		alpine)
@@ -568,15 +564,13 @@ buildRequiredPackageLists() {
 	esac
 	if test -n "$buildRequiredPackageLists_persistent"; then
 		PACKAGES_PERSISTENT="$(expandPackagesToBeInstalled $buildRequiredPackageLists_persistent)"
-		if test -s "$IPE_ERRFILE"; then
-			cat "$IPE_ERRFILE" >&2
+		if test -s "$IPE_ERRFLAG_FILE"; then
 			exit 1
 		fi
 	fi
 	if test -n "$buildRequiredPackageLists_volatile"; then
 		buildRequiredPackageLists_packages="$(expandPackagesToBeInstalled $buildRequiredPackageLists_volatile)"
-		if test -s "$IPE_ERRFILE"; then
-			cat "$IPE_ERRFILE" >&2
+		if test -s "$IPE_ERRFLAG_FILE"; then
 			exit 1
 		fi
 		resetIFS
@@ -602,9 +596,10 @@ expandPackagesToBeInstalled() {
 		alpine)
 			expandPackagesToBeInstalled_log="$(apk add --simulate $@ 2>&1 || printf '\nERROR: apk failed\n')"
 			if test -n "$(printf '%s' "$expandPackagesToBeInstalled_log" | grep -E '^ERROR:')"; then
-				printf 'FAILED TO LIST THE WHOLE PACKAGE LIST FOR\n' >"$IPE_ERRFILE"
-				printf '%s ' "$@" >>"$IPE_ERRFILE"
-				printf '\n\nCOMMAND OUTPUT:\n%s\n' "$expandPackagesToBeInstalled_log" >>"$IPE_ERRFILE"
+				printf 'FAILED TO LIST THE WHOLE PACKAGE LIST FOR\n' >&2
+				printf '%s ' "$@" >&2
+				printf '\n\nCOMMAND OUTPUT:\n%s\n' "$expandPackagesToBeInstalled_log" >&2
+				echo 'y' >"$IPE_ERRFLAG_FILE"
 				exit 1
 			fi
 			IFS='
@@ -619,9 +614,10 @@ expandPackagesToBeInstalled() {
 		debian)
 			expandPackagesToBeInstalled_log="$(DEBIAN_FRONTEND=noninteractive apt-get install -sy $@ 2>&1 || printf '\nE: apt-get failed\n')"
 			if test -n "$(printf '%s' "$expandPackagesToBeInstalled_log" | grep -E '^E:')"; then
-				printf 'FAILED TO LIST THE WHOLE PACKAGE LIST FOR\n' >"$IPE_ERRFILE"
-				printf '%s ' "$@" >"$IPE_ERRFILE"
-				printf '\n\nCOMMAND OUTPUT:\n%s\n' "$expandPackagesToBeInstalled_log" >"$IPE_ERRFILE"
+				printf 'FAILED TO LIST THE WHOLE PACKAGE LIST FOR\n' >&2
+				printf '%s ' "$@" >&2
+				printf '\n\nCOMMAND OUTPUT:\n%s\n' "$expandPackagesToBeInstalled_log" >&2
+				echo 'y' >"$IPE_ERRFLAG_FILE"
 				exit 1
 			fi
 			expandPackagesToBeInstalled_inNewPackages=0
@@ -1142,7 +1138,7 @@ cleanup() {
 
 resetIFS
 mkdir -p /tmp/src
-IPE_ERRFILE="$(mktemp -p /tmp/src)"
+IPE_ERRFLAG_FILE="$(mktemp -p /tmp/src)"
 PHP_MAJMIN_VERSION=$(getPHPMajorMinor)
 case "$PHP_MAJMIN_VERSION" in
 	506 | 700 | 701 | 702 | 703 | 704) ;;
@@ -1159,7 +1155,8 @@ fi
 
 sortModulesToInstall
 
-if buildRequiredPackageLists $PHP_MAJMIN_VERSION $PHP_MODULES_TO_INSTALL; then
+buildRequiredPackageLists $PHP_MAJMIN_VERSION $PHP_MODULES_TO_INSTALL
+if test -n "$PACKAGES_PERSISTENT$PACKAGES_VOLATILE"; then
 	installRequiredPackages
 fi
 docker-php-source extract
diff --git a/scripts/travisci-test-extensions b/scripts/travisci-test-extensions
index 34d3eba..23ea899 100755
--- a/scripts/travisci-test-extensions
+++ b/scripts/travisci-test-extensions
@@ -28,123 +28,29 @@ getDockerImageName() {
 			getDockerImageName_version="$2"
 			;;
 	esac
-	getDockerImageName_suffix='-cli'
+	getDockerImageName_suffix='cli'
 	getDockerImageName_reqs="$TRAVIS_BUILD_DIR/data/special-requirements"
 	if test -f "$getDockerImageName_reqs"; then
 		IFS=' '
 		for getDockerImageName_testExtension in $1; do
 			if test -n "$(cat "$getDockerImageName_reqs" | grep -E "^$getDockerImageName_testExtension[ \t]+zts[ \t]*$")"; then
-				getDockerImageName_suffix="-zts"
+				getDockerImageName_suffix='zts'
 			fi
 		done
 	fi
-	getDockerImageName_distro="-$DOCKER_DISTRO"
-	case "$DOCKER_DISTRO" in
-		alpine3.4)
-			# available for PHP from version 5.6 to version 7.1
-			case "$2" in
-				5.* | 7.0 | 7.1) ;;
-				*)
-					return
-					;;
-			esac
-			;;
-		alpine3.6)
-			# available for PHP 7.2
-			case "$2" in
-				7.2) ;;
-				*)
-					return
-					;;
-			esac
-			;;
-		alpine3.7)
-			# available for PHP from version 5.6 to version 7.2
-			# default Alpine one for PHP 7.0
-			case "$2" in
-				7.0)
-					#getDockerImageName_distro='-alpine'
-					;;
-				5.* | 7.1 | 7.2) ;;
-				*)
-					return
-					;;
-			esac
-			;;
-		alpine3.8)
-			# available for PHP from version 5.6 to version 7.3 (except PHP 7.0)
-			# default Alpine one for PHP 5.6
-			case "$2" in
-				5.6)
-					#getDockerImageName_distro='-alpine'
-					;;
-				5.* | 7.1 | 7.2 | 7.3) ;;
-				*)
-					return
-					;;
-			esac
-			;;
-		alpine3.9)
-			# available for PHP from version 7.1 to version 7.3
-			case "$2" in
-				7.1 | 7.2 | 7.3) ;;
-				*)
-					return
-					;;
-			esac
-			;;
-		alpine3.10)
-			# available for PHP from version 7.1
-			# default Alpine one for PHP 7.1 -> 7.4
-			case "$2" in
-				7.1 | 7.2 | 7.3 | 7.4)
-					#getDockerImageName_distro='-alpine'
-					;;
-				5.* | 7.0)
-					return
-					;;
-			esac
-			;;
-		jessie) # Debian 8
-			# available for PHP up to version 7.1
-			case "$2" in
-				5.* | 7.0 | 7.1) ;;
-				*)
-					return
-					;;
-			esac
-			;;
-		stretch) # Debian 9
-			# available for PHP up to version 7.3
-			# default one for PHP 5.6 -> 7.0
-			case "$2" in
-				5.* | 7.0)
-					#getDockerImageName_distro=''
-					;;
-				7.1 | 7.2 | 7.3) ;;
-				*)
-					return
-					;;
-			esac
-			;;
-		buster) # Debian 10
-			# available for PHP from version 7.1
-			# default one for PHP 7.1 -> 7.4
-			case "$2" in
-				7.1 | 7.2 | 7.3 | 7.4)
-					#getDockerImageName_distro=''
-					;;
-				5.* | 7.0)
-					return
-					;;
-			esac
-			;;
-		*)
-			printf 'Unrecognized value of DOCKER_DISTRO environment variable (%s)\n' "$DOCKER_DISTRO" >&2
-			return 1
-			;;
-	esac
-	printf 'php:%s%s%s' "$getDockerImageName_version" "$getDockerImageName_suffix" "$getDockerImageName_distro"
+	getDockerImageName_imageName="$(printf 'php:%s-%s-%s' "$getDockerImageName_version" "$getDockerImageName_suffix" "$DOCKER_DISTRO")"
+	if test -z "$(docker images -q "$getDockerImageName_imageName" 2>/dev/null)"; then
+		getDockerImageName_log="$(docker pull "$getDockerImageName_imageName" 2>&1 || true)"
+		if test -z "$(docker images -q "$getDockerImageName_imageName" 2>/dev/null)"; then
+			if test "${getDockerImageName_log#*manifest unknown}" != "$getDockerImageName_log" || test "${getDockerImageName_log#*manifest for * not found}" != "$getDockerImageName_log"; then
+				true
+				return
+			fi
+			printf '%s\n' "$getDockerImageName_log" >&2
+			exit 1
+		fi
+	fi
+	printf '%s' "$getDockerImageName_imageName"
 }
 
 # Test an extension
@@ -163,6 +69,9 @@ testExtension() {
 		return 1
 	fi
 	testExtension_Image="$(getDockerImageName "$1" "$2")"
+	if test $? -ne 0; then
+		exit 1
+	fi
 	if test -z "$testExtension_Image"; then
 		printf ' - Docker image not available\n'
 		return 0