diff --git a/lib/manager/poetry/artifacts.ts b/lib/manager/poetry/artifacts.ts
index a1fa62e732e9bbe60736894494ee06e406956ae2..1faec9e9f02ef65c16a8e12a0dfd05419ded1739 100644
--- a/lib/manager/poetry/artifacts.ts
+++ b/lib/manager/poetry/artifacts.ts
@@ -99,7 +99,7 @@ export async function updateArtifacts(
       {
         artifactError: {
           lockFile: lockFileName,
-          stderr: err.message,
+          stderr: err.stdout + '\n' + err.stderr,
         },
       },
     ];