--- a/ExternalAddress.st	Tue May 29 13:29:04 2018 +0200
+++ b/ExternalAddress.st	Tue Jul 17 09:07:17 2018 +0200
@@ -1,5 +1,6 @@
 "
  COPYRIGHT (c) 1995 by Claus Gittinger
+ COPYRIGHT (c) 2018 Jan Vrany
 	      All Rights Reserved
 
  This software is furnished under a license and may be used
@@ -25,6 +26,7 @@
 copyright
 "
  COPYRIGHT (c) 1995 by Claus Gittinger
+ COPYRIGHT (c) 2017 Jan Vrany
 	      All Rights Reserved
 
  This software is furnished under a license and may be used
@@ -351,13 +353,12 @@
 
     unsigned INT addr;
 
-    if (__isSmallInteger(anInteger)) {
+    if (anInteger == nil) {
+    	addr = (unsigned INT)NULL;
+    } else if (__isSmallInteger(anInteger)) {
         addr = __intVal(anInteger);
     } else {
-        addr = __unsignedLongIntVal(anInteger);
-        if (addr == 0) {
-            console_printf("invalid address argument in ExternalAddress>>setAddress\n");
-        }
+        addr = __unsignedLongIntVal(anInteger);    
     }
     __INST(address_) = (OBJ)addr;
 %}