diff --git a/tests/regression.at b/tests/regression.at
index 046459bc..f6b5fe0d 100644
--- a/tests/regression.at
+++ b/tests/regression.at
@@ -279,7 +279,7 @@ expr:
 }
 ]])
 
-AT_CHECK([bison input.y input.c -v], 0, [], [])
+AT_CHECK([bison input.y -o input.c -v], 0, [], [])
 
 # Check the contents of the report.
 AT_CHECK([cat input.output], [],