diff --git a/pkg/testutil/testutil.go b/pkg/testutil/testutil.go
index a67eded1e..db2dd3285 100644
--- a/pkg/testutil/testutil.go
+++ b/pkg/testutil/testutil.go
@@ -50,7 +50,7 @@ func MustNewURL(t *testing.T, s string) *url.URL {
 
 // FatalStack helps to fatal the test and print out the stacks of all running goroutines.
 func FatalStack(t *testing.T, s string) {
-	stackTrace := make([]byte, 8*1024)
+	stackTrace := make([]byte, 1024*1024)
 	n := runtime.Stack(stackTrace, true)
 	t.Error(string(stackTrace[:n]))
 	t.Fatalf(s)