diff --git a/pytools/prefork.py b/pytools/prefork.py
index 9cb90541ccc9a0ba194eb73cec87fc5cbef1aeeb..6932bc977498ff6e6eb4dcddeb8928a845311076 100644
--- a/pytools/prefork.py
+++ b/pytools/prefork.py
@@ -65,7 +65,12 @@ class DirectForker(object):
         return retc
 
     def waitall(self):
-        return {aid: self.wait(aid) for aid in list(self.apids)}
+        rets = {}
+
+        for aid in list(self.apids):
+            rets[aid] = self.wait(aid)
+
+        return rets
 
 
 def _send_packet(sock, data):