--- a/NonPositionableExternalStream.st	Mon Oct 29 17:56:35 2018 +0100
+++ b/NonPositionableExternalStream.st	Mon Oct 29 18:07:09 2018 +0100
@@ -274,6 +274,12 @@
     aBoolean ifFalse:[
 	super buffered:false.
     ].
+!
+
+setCommandString:dummyString
+    "dummy for PipeStream compatibility"
+
+    "Created: / 29-10-2018 / 18:06:44 / Claus Gittinger"
 ! !
 
 !NonPositionableExternalStream methodsFor:'error handling'!