diff --git a/Makefile b/Makefile
index ef1bed5..b0bcc58 100644
--- a/Makefile
+++ b/Makefile
@@ -1 +1,9 @@
 include ../../PluginsMakefile.mk
+
+install-ext: ## Install PHP extensions required by this plugin (sqlsrv). Re-run after any container rebuild.
+	$(COMPOSE) exec --user root app bash -c "\
+		apt-get update -yq \
+		&& apt-get install -yq --no-install-recommends unixodbc-dev \
+		&& rm -rf /var/lib/apt/lists/* \
+		&& pecl install sqlsrv \
+		&& docker-php-ext-enable sqlsrv"
diff --git a/README.md b/README.md
index f6fefa3..42f7d15 100644
--- a/README.md
+++ b/README.md
@@ -23,6 +23,18 @@ Plugin to synchronize computers from SCCM (version 1802) to GLPI.
 ![GLPISCCMPluginSchema](screenshots/schema.png "GLPISCCMPluginSchema")
 
 
+## Development setup
+
+This plugin requires the `sqlsrv` PHP extension (PECL), which is not included in the base GLPI development image.
+
+After starting the containers (`make` from the GLPI root), install it once:
+
+```bash
+make install-ext
+```
+
+Re-run this command after any container rebuild.
+
 ## Documentation
 
 We maintain a detailed documentation here -> [Documentation](https://glpi-plugins.readthedocs.io/en/latest/sccm/index.html)