diff --git a/.github/workflows/test-extensions.yml b/.github/workflows/test-extensions.yml
index 207801c..ae44f60 100644
--- a/.github/workflows/test-extensions.yml
+++ b/.github/workflows/test-extensions.yml
@@ -62,8 +62,6 @@ jobs:
       fail-fast: true
       matrix:
         distro:
-          - alpine3.7
-          - alpine3.8
           - alpine3.9
           - alpine3.10
           - alpine3.11
diff --git a/.github/workflows/test-recent-extensions.yml b/.github/workflows/test-recent-extensions.yml
index eb2191f..f2d8a6b 100644
--- a/.github/workflows/test-recent-extensions.yml
+++ b/.github/workflows/test-recent-extensions.yml
@@ -37,8 +37,6 @@ jobs:
       fail-fast: false
       matrix:
         distro:
-          - alpine3.7
-          - alpine3.8
           - alpine3.9
           - alpine3.10
           - alpine3.11
diff --git a/README.md b/README.md
index 1ca4d90..db8e378 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,11 @@ 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:
+
+- Debian-based docker images: since jessie (Debian 8) (minimum PHP version: 5.5)
+- Alpine-based docker images: since Alpine 3.9 (minimum PHP version: 7.1)
+
 See also the notes in the [Special requirements](#special-requirements) section.
 
 ## Usage
diff --git a/data/special-requirements b/data/special-requirements
index 29d59aa..aecb35d 100644
--- a/data/special-requirements
+++ b/data/special-requirements
@@ -1,14 +1,14 @@
-cassandra !alpine3.7 !alpine3.8 !jessie !stretch !buster !bullseye
-ddtrace !alpine3.7 !alpine3.8 !jessie
-geos !alpine3.7 !alpine3.8 !alpine3.9 !alpine3.10
+cassandra !jessie !stretch !buster !bullseye
+ddtrace !jessie
+geos !alpine3.9 !alpine3.10
 lz4 !jessie
-memprof !alpine3.7 !alpine3.8 !alpine3.9 !alpine3.10 !alpine3.11 !alpine3.12 !alpine3.13 !alpine3.14 !alpine3.15
+memprof !alpine3.9 !alpine3.10 !alpine3.11 !alpine3.12 !alpine3.13 !alpine3.14 !alpine3.15
 parallel zts
 parle !jessie
-pdo_sqlsrv !alpine3.7 !alpine3.8 !arm
+pdo_sqlsrv !arm
 pthreads zts
-simdjson !alpine3.7 !alpine3.8 !jessie !stretch
+simdjson !jessie !stretch
 sodium !jessie
-sqlsrv !alpine3.7 !alpine3.8 !7.1-alpine3.9 !7.1-alpine3.10 !arm
+sqlsrv !7.1-alpine3.9 !7.1-alpine3.10 !arm
 tensor !alpine3.15 !alpine3.16
-vips !alpine3.7 !alpine3.8 !alpine3.9 !jessie
+vips !alpine3.9 !jessie