diff --git a/frappe/__init__.py b/frappe/__init__.py
index 65a7fc818c..11263a831e 100644
--- a/frappe/__init__.py
+++ b/frappe/__init__.py
@@ -188,6 +188,9 @@ def connect(site=None, db_name=None):
 	local.db = Database(user=db_name or local.conf.db_name)
 	set_user("Administrator")
 
+	for hook in get_hooks("connect") or []:
+		get_attr(hook)()
+
 def connect_read_only():
 	from frappe.database import Database
 
diff --git a/frappe/exceptions.py b/frappe/exceptions.py
index 3a8548a6e0..a1b4ef2024 100644
--- a/frappe/exceptions.py
+++ b/frappe/exceptions.py
@@ -84,3 +84,4 @@ class RetryBackgroundJobError(Exception): pass
 class DocumentLockedError(ValidationError): pass
 class CircularLinkingError(ValidationError): pass
 class SecurityException(Exception): pass
+class IncompatibleApp(ValidationError): pass