diff --git a/src/lib/Hydra/Helper/BuildDiff.pm b/src/lib/Hydra/Helper/BuildDiff.pm
index 7655bf4d..fb6e6543 100644
--- a/src/lib/Hydra/Helper/BuildDiff.pm
+++ b/src/lib/Hydra/Helper/BuildDiff.pm
@@ -18,7 +18,7 @@ use Data::Dumper;
 sub buildDiff {
     my ($builds, $builds2) = @_;
 
-    my $ret = [
+    my $ret = {
         stillSucceed => [],
         stillFail => [],
         nowSucceed => [],
@@ -28,7 +28,7 @@ sub buildDiff {
         unfinished => [],
         aborted => [],
         failed => [],
-    ];
+    };
 
     my $n = 0;
     foreach my $build (@{$builds}) {
diff --git a/t/Helper/BuildDiff.t b/t/Helper/BuildDiff.t
index 86bf3fba..35d7e8c2 100644
--- a/t/Helper/BuildDiff.t
+++ b/t/Helper/BuildDiff.t
@@ -9,7 +9,7 @@ my $ctx = test_context();
 
 subtest "response" => sub {
     my $ret = buildDiff([], []);
-    is($ret, [
+    is($ret, {
         stillSucceed => [],
         stillFail => [],
         nowSucceed => [],
@@ -19,7 +19,7 @@ subtest "response" => sub {
         unfinished => [],
         aborted => [],
         failed => [],
-    ]);
+    });
 };
 
 is(1, 1);