diff --git a/justfile b/justfile
index 41f9c7c6..0bbfc5c6 100644
--- a/justfile
+++ b/justfile
@@ -13,7 +13,7 @@ ci-up-val:
     python3 planning/unified/deps/unified-planning/up_test_cases/report.py aries-val -e up_aries_tests
 
 # Solve a UP test case
-up-solve problem:
+up-solve +problem:
     python3 planning/unified/scripts/cli.py {{problem}}
 
 # Export a UP test case to a protobuf binary file (/tmp/problem.upp)