diff --git a/app/check-composer-json.sh b/app/check-composer-json.sh
new file mode 100755
index 0000000000..1af75152cf
--- /dev/null
+++ b/app/check-composer-json.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+
+if [ -h "composer.json" ]; then
+    echo 'Please run composer install in the app/ subfolder.'
+    exit 1
+fi
diff --git a/app/composer.json b/app/composer.json
index f0b015d037..941a81e78c 100644
--- a/app/composer.json
+++ b/app/composer.json
@@ -147,10 +147,10 @@
     },
     "scripts": {
         "pre-install-cmd": [
-            "if [ -h \"composer.json\" ]; then echo 'Please run composer install in the app/ subfolder.'; exit 1; fi"
+            "./app/check-composer-json.sh"
         ],
         "pre-update-cmd": [
-            "if [ -h \"composer.json\" ]; then echo 'Please run composer install in the app/ subfolder.'; exit 1; fi"
+            "./app/check-composer-json.sh"
         ],
         "post-install-cmd": [
             "App\\Environment::checkEnvironment",