diff --git a/cypress/integration/table_multiselect.js b/cypress/integration/table_multiselect.js
index 8b83a0d914..faa72d63a5 100644
--- a/cypress/integration/table_multiselect.js
+++ b/cypress/integration/table_multiselect.js
@@ -8,7 +8,7 @@ context('Table MultiSelect', () => {
 	it('select value from multiselect dropdown', () => {
 		cy.new_form('Assignment Rule');
 		cy.fill_field('__newname', name);
-		cy.fill_field('document_type', 'ToDo');
+		cy.fill_field('document_type', 'Blog Post');
 		cy.fill_field('assign_condition', 'status=="Open"', 'Code');
 		cy.get('input[data-fieldname="users"]').focus().as('input');
 		cy.get('input[data-fieldname="users"] + ul').should('be.visible');
diff --git a/frappe/automation/doctype/assignment_rule/assignment_rule.js b/frappe/automation/doctype/assignment_rule/assignment_rule.js
index ee1a076465..97bed4f8f3 100644
--- a/frappe/automation/doctype/assignment_rule/assignment_rule.js
+++ b/frappe/automation/doctype/assignment_rule/assignment_rule.js
@@ -9,6 +9,16 @@ frappe.ui.form.on('Assignment Rule', {
 		frm.events.rule(frm);
 	},
 
+	setup: function(frm) {
+		frm.set_query("document_type", () => {
+			return {
+				filters: {
+					name: ["!=", "ToDo"]
+				}
+			};
+		});
+	},
+
 	document_type: function(frm) {
 		frm.trigger('set_options');
 	},
diff --git a/frappe/automation/doctype/assignment_rule/assignment_rule.py b/frappe/automation/doctype/assignment_rule/assignment_rule.py
index d20398d564..c673d5ceeb 100644
--- a/frappe/automation/doctype/assignment_rule/assignment_rule.py
+++ b/frappe/automation/doctype/assignment_rule/assignment_rule.py
@@ -18,6 +18,8 @@ class AssignmentRule(Document):
 		if not len(set(assignment_days)) == len(assignment_days):
 			repeated_days = get_repeated(assignment_days)
 			frappe.throw(_("Assignment Day {0} has been repeated.").format(frappe.bold(repeated_days)))
+		if self.document_type == 'ToDo':
+			frappe.throw(_('Assignment Rule is not allowed on {0} document type').format(frappe.bold("ToDo")))
 
 	def on_update(self):
 		clear_assignment_rule_cache(self)
@@ -298,4 +300,4 @@ def get_repeated(values):
 
 def clear_assignment_rule_cache(rule):
 	frappe.cache_manager.clear_doctype_map('Assignment Rule', rule.document_type)
-	frappe.cache_manager.clear_doctype_map('Assignment Rule', 'due_date_rules_for_' + rule.document_type)
\ No newline at end of file
+	frappe.cache_manager.clear_doctype_map('Assignment Rule', 'due_date_rules_for_' + rule.document_type)