diff --git a/frappe/database/database.py b/frappe/database/database.py
index b1b5abffca..82a7e6f919 100644
--- a/frappe/database/database.py
+++ b/frappe/database/database.py
@@ -919,8 +919,8 @@ class Database(object):
 			return dn
 
 		if isinstance(dt, dict):
-			_dt = dt.pop("doctype")
-			dt, dn = _dt, dt
+			dt = dt.copy() # don't modify the original dict
+			dt, dn = dt.pop("doctype"), dt
 
 		return self.get_value(dt, dn, ignore=True, cache=cache)
 
diff --git a/frappe/tests/test_db.py b/frappe/tests/test_db.py
index 19b683aa75..10c601db00 100644
--- a/frappe/tests/test_db.py
+++ b/frappe/tests/test_db.py
@@ -327,7 +327,13 @@ class TestDB(unittest.TestCase):
 		self.assertEqual(frappe.db.exists(dt, dn, cache=True), dn)
 		self.assertEqual(frappe.db.exists(dt, dn), dn)
 		self.assertEqual(frappe.db.exists(dt, {"name": ("=", dn)}), dn)
-		self.assertEqual(frappe.db.exists({"doctype": dt, "name": ("like", "Admin%")}), dn)
+
+		filters = {"doctype": dt, "name": ("like", "Admin%")}
+		self.assertEqual(frappe.db.exists(filters), dn)
+		self.assertEqual(
+			filters["doctype"], dt
+		)  # make sure that doctype was not removed from filters
+
 		self.assertEqual(frappe.db.exists(dt, [["name", "=", dn]]), dn)