diff --git a/lib/manager/pip_setup/extract.js b/lib/manager/pip_setup/extract.js
index 1673dcdceefbdca06e06e556934c8b281283e690..cab033279550ce902062693cc9d5d3ff7839b4e3 100644
--- a/lib/manager/pip_setup/extract.js
+++ b/lib/manager/pip_setup/extract.js
@@ -57,7 +57,10 @@ async function extractSetupFile(content, packageFile, config) {
   }
   // istanbul ignore if
   if (stderr) {
-    logger.warn({ stdout, stderr }, 'Error in read setup file');
+    stderr = stderr.replace(/.*\n\s*import imp/, '').trim();
+    if (stderr.length) {
+      logger.warn({ stdout, stderr }, 'Error in read setup file');
+    }
   }
   return JSON.parse(stdout);
 }