diff --git a/test/functional/rpc_scantxoutset.py b/test/functional/rpc_scantxoutset.py
index dca965aacb053..85c5d6c84c002 100755
--- a/test/functional/rpc_scantxoutset.py
+++ b/test/functional/rpc_scantxoutset.py
@@ -120,6 +120,9 @@ def run_test(self):
         assert_equal(self.nodes[0].scantxoutset("status"), None)
         assert_equal(self.nodes[0].scantxoutset("abort"), False)
 
+        # check that first arg is needed
+        assert_raises_rpc_error(-1, "scantxoutset \"action\" ( [scanobjects,...] )", self.nodes[0].scantxoutset)
+
         # Check that second arg is needed for start
         assert_raises_rpc_error(-1, "scanobjects argument is required for the start action", self.nodes[0].scantxoutset, "start")