diff --git a/tests/gc-auto.sh b/tests/gc-auto.sh
index 1e91282d..4b1f6374 100644
--- a/tests/gc-auto.sh
+++ b/tests/gc-auto.sh
@@ -29,7 +29,7 @@ with import ./config.nix; mkDerivation {
 EOF
 )
 
-nix build -o $TEST_ROOT/result-A -L "($expr)" \
+nix build -v -o $TEST_ROOT/result-A -L "($expr)" \
     --min-free 1000 --max-free 2000 --min-free-check-interval 1 &
 pid=$!
 
@@ -50,7 +50,7 @@ with import ./config.nix; mkDerivation {
 EOF
 )
 
-nix build -o $TEST_ROOT/result-B -L "($expr2)" \
+nix build -v -o $TEST_ROOT/result-B -L "($expr2)" \
     --min-free 1000 --max-free 2000 --min-free-check-interval 1
 
 wait "$pid"