diff --git a/craft_parts/errors.py b/craft_parts/errors.py
index b31196fdf..18008c7cc 100644
--- a/craft_parts/errors.py
+++ b/craft_parts/errors.py
@@ -518,9 +518,9 @@ def details(self) -> str | None:
 
         Discards all trace lines that come before the last-executed script line
         """
+        if self.stderr is None:
+            return super().details
         with contextlib.closing(StringIO()) as details_io:
-            if self.stderr is None:
-                return None
 
             stderr = self.stderr.decode("utf-8", errors="replace")
             details_io.write("\nCaptured standard error:")