diff --git a/scripts/grade.sh b/scripts/grade.sh
index 50e611d..9aef428 100755
--- a/scripts/grade.sh
+++ b/scripts/grade.sh
@@ -9,10 +9,7 @@ BASEDIR=$(dirname "$0")
 source $BASEDIR/test_cases.sh
 source $BASEDIR/grade-utils.sh
 
-RUNNERS=(
-    "cargo"
-    "cargo --release"
-)
+RUNNERS="cargo"
 
 # Lints.
 run_linters || exit 0