diff --git a/README.md b/README.md
index e435a8e..2eded56 100644
--- a/README.md
+++ b/README.md
@@ -36,9 +36,14 @@ Or macOS:
 brew install vips
 ```
 
-You'll need to [enable FFI in your
-PHP](https://www.php.net/manual/en/ffi.configuration.php), then add vips
-to your `composer.json`:
+php-vips does not yet support FFI preloading, so you need to enable FFI globally by setting `ffi.enable` to `true`. This has some security implications, since anyone who can run php on your server can use it to call any native library they have access to.
+
+Of course if attackers are running their own PHP code on your webserver you
+are probably already toast, unfortunately.
+
+For more information see the [FFI Runtime Configuration](https://www.php.net/manual/en/ffi.configuration.php).
+
+Then add vips to your `composer.json`:
 
 ```
 "require": {
@@ -46,13 +51,6 @@ to your `composer.json`:
 }
 ```
 
-php-vips does not yet support preloading, so you need to enable FFI globally.
-This has some security implications, since anyone who can run php on your
-server can use it to call any native library they have access to.
-
-Of course if attackers are running their own PHP code on your webserver you
-are probably already toast, unfortunately.
-
 Finally, on php 8.3 and later you need to disable stack overflow
 tests. php-vips executes FFI callbacks off the main thread and this confuses
 those checks, at least in php 8.3.0.
diff --git a/src/FFI.php b/src/FFI.php
index 722065d..0636708 100644
--- a/src/FFI.php
+++ b/src/FFI.php
@@ -315,6 +315,9 @@ private static function init(): void
             }
             $msg .= ". Make sure that you've installed libvips and that '$vips_libname'";
             $msg .= " is on your system's library search path.";
+            if ('preload' === ini_get('ffi.enable')) {
+                $msg .= "FFI is not enabled globally; this will prevent PHP from locating '$vips_libname'.";
+            }
             throw new Exception($msg);
         }