diff --git a/mitogen/parent.py b/mitogen/parent.py
index f2dacb09..556f38c6 100644
--- a/mitogen/parent.py
+++ b/mitogen/parent.py
@@ -285,6 +285,9 @@ def create_child(args, merge_stdio=False, stderr_pipe=False, preexec_fn=None):
     except Exception:
         childfp.close()
         parentfp.close()
+        if stderr_pipe:
+            os.close(stderr_r)
+            os.close(stderr_w)
         raise
 
     if stderr_pipe: