diff --git a/tests/common/util.rs b/tests/common/util.rs
index 5e1424ca4..ae93af20d 100644
--- a/tests/common/util.rs
+++ b/tests/common/util.rs
@@ -221,7 +221,7 @@ impl CmdResult {
         assert!(
             self.stdout.is_empty(),
             "Expected stdout to be empty, but it's:\n{}",
-            self.stderr_str()
+            self.stdout_str()
         );
         self
     }