diff --git a/README.md b/README.md
index f3b0389..a04019f 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,8 @@ 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.
 
-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`)
+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`).
+See also the notes in the [Special requirements](#special-requirements) section.
 
 
 ## Usage
diff --git a/scripts/ci-test-extensions b/scripts/ci-test-extensions
index 43a8c38..47ba0e6 100755
--- a/scripts/ci-test-extensions
+++ b/scripts/ci-test-extensions
@@ -76,6 +76,29 @@ extractExtensionsFromData() {
 	EXTENSIONS_TO_BE_TESTED="${EXTENSIONS_TO_BE_TESTED# }"
 }
 
+# Remove from the EXTENSIONS_TO_BE_TESTED variable the extensions that are
+# not supported in the distro specified in the data/special-requirements file
+
+# Update: EXTENSIONS_TO_BE_TESTED
+filterUnsupportedExensionsForDistro() {
+	if test -z "$EXTENSIONS_TO_BE_TESTED"; then
+		return
+	fi
+	filterUnsupportedExensionsForDistro_reqs="$CI_BUILD_DIR/data/special-requirements"
+	if ! test -f "$filterUnsupportedExensionsForDistro_reqs"; then
+		return
+	fi
+	filterUnsupportedExensionsForDistro_filtered=''
+	for filterUnsupportedExensionsForDistro_extension in "$EXTENSIONS_TO_BE_TESTED"; do
+		if stringInList "!$DOCKER_DISTRO" "$(cat "$filterUnsupportedExensionsForDistro_reqs" | grep -E "^$filterUnsupportedExensionsForDistro_extension[ \t]")"; then
+			printf 'Note: extension "%s" is not supported for distro "%s"\n' "$filterUnsupportedExensionsForDistro_extension" "$DOCKER_DISTRO"
+		else
+			filterUnsupportedExensionsForDistro_filtered="$filterUnsupportedExensionsForDistro_filtered $filterUnsupportedExensionsForDistro_extension"
+		fi
+	done
+	EXTENSIONS_TO_BE_TESTED="${filterUnsupportedExensionsForDistro_filtered# }"
+}
+
 # Get the docker image ID for a PHP extension and a PHP version
 #
 # Arguments:
@@ -262,6 +285,8 @@ if test -z "${DOCKER_DISTRO:-}"; then
 	exit 1
 fi
 
+. "$CI_BUILD_DIR/scripts/common"
+
 case "${1:-}" in
 	from-commits)
 		if test -z "${2:-}"; then
@@ -289,13 +314,13 @@ case "${1:-}" in
 		;;
 esac
 
+filterUnsupportedExensionsForDistro
+
 if test -z "$EXTENSIONS_TO_BE_TESTED"; then
 	echo 'No extensions to be tested.'
 	exit 0
 fi
 
-. "$CI_BUILD_DIR/scripts/common"
-
 printf '### EXTENSIONS TO BE TESTED: %s\n' "$EXTENSIONS_TO_BE_TESTED"
 SOME_TEST_FAILED=0
 IFS='
diff --git a/scripts/update-readme b/scripts/update-readme
index 6618fea..bf65489 100755
--- a/scripts/update-readme
+++ b/scripts/update-readme
@@ -143,25 +143,43 @@ generateExtensionsTable() {
 # Output:
 # the markdown table
 generateSpecialRequirementsTable() {
-	generateSpecialRequirementsTable_started=''
+	generateSpecialRequirementsTable_started=0
 	IFS='
 '
 	for generateSpecialRequirementsTable_line in $(cat -- "$1" | sort); do
-		if test -z "$generateSpecialRequirementsTable_started"; then
-			printf '| Extension | Requirements |\n'
-			printf '|:---:|:---:|\n'
-			generateSpecialRequirementsTable_started='y'
-		fi
 		resetIFS
-		generateSpecialRequirementsTable_requirement="$(echo "$generateSpecialRequirementsTable_line" | sed -E 's/^\s*\w+\s+//')"
-		case "$generateSpecialRequirementsTable_requirement" in
-			zts)
-				generateSpecialRequirementsTable_requirement='Requires images with PHP compiled with thread-safety enabled (`zts`).'
-				;;
-		esac
-		printf '| %s | %s |\n' \
-			"$(echo "$generateSpecialRequirementsTable_line" | awk '{print $1;}')" \
-			"$generateSpecialRequirementsTable_requirement"
+		generateSpecialRequirementsTable_index=0
+		for generateSpecialRequirementsTable_chunk in $generateSpecialRequirementsTable_line; do
+			if test $generateSpecialRequirementsTable_index -eq 0; then
+				generateSpecialRequirementsTable_extension="$generateSpecialRequirementsTable_chunk"
+			else
+				if test $generateSpecialRequirementsTable_index -eq 1; then
+					generateSpecialRequirementsTable_requirements=''
+				elif test $generateSpecialRequirementsTable_index -eq 2; then
+					generateSpecialRequirementsTable_requirements="$(printf -- '&bull; %s<br />&bull; ' "$generateSpecialRequirementsTable_requirements")"
+				else
+					generateSpecialRequirementsTable_requirements="$(printf '%s<br />&bull; ' "$generateSpecialRequirementsTable_requirements")"
+				fi
+				case "$generateSpecialRequirementsTable_chunk" in
+					zts)
+						generateSpecialRequirementsTable_chunk='Requires images with PHP compiled with thread-safety enabled (`zts`).'
+						;;
+					!*)
+						generateSpecialRequirementsTable_chunk="$(printf 'Not available in `%s` docker images' "${generateSpecialRequirementsTable_chunk#!}")"
+						;;
+				esac
+				generateSpecialRequirementsTable_requirements="$(printf '%s%s' "$generateSpecialRequirementsTable_requirements" "$generateSpecialRequirementsTable_chunk")"
+			fi
+			generateSpecialRequirementsTable_index=$((generateSpecialRequirementsTable_index + 1))
+		done
+		if test $generateSpecialRequirementsTable_index -gt 1; then
+			if test $generateSpecialRequirementsTable_started -eq 0; then
+				printf '| Extension | Requirements |\n'
+				printf '|---|---|\n'
+				generateSpecialRequirementsTable_started=1
+			fi
+			printf '| %s | %s |\n' "$generateSpecialRequirementsTable_extension" "$generateSpecialRequirementsTable_requirements"
+		fi
 	done
 }