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 3fc4978d18..2299a066c9 100644
--- a/app/composer.json
+++ b/app/composer.json
@@ -146,6 +146,12 @@
         "guzzlehttp/psr7": "<=1.8.3, >=2.0.0, <=2.1.0"
     },
     "scripts": {
+        "pre-install-cmd": [
+            "./check-composer-json.sh"
+        ],
+        "pre-update-cmd": [
+            "./check-composer-json.sh"
+        ],
         "post-install-cmd": [
             "App\\Environment::checkEnvironment",
             "@auto-scripts"
diff --git a/check-composer-json.sh b/check-composer-json.sh
new file mode 120000
index 0000000000..e041c594bb
--- /dev/null
+++ b/check-composer-json.sh
@@ -0,0 +1 @@
+app/check-composer-json.sh
\ No newline at end of file
diff --git a/composer.json b/composer.json
new file mode 120000
index 0000000000..44141f74d0
--- /dev/null
+++ b/composer.json
@@ -0,0 +1 @@
+app/composer.json
\ No newline at end of file