diff --git a/src/smblib/smblib.c b/src/smblib/smblib.c
index fc79510942fc4ca740aba04e179d487b3cdd4667..3a11dd96c1c2c1dcbb07934fceccd1ee6d45e3cf 100644
--- a/src/smblib/smblib.c
+++ b/src/smblib/smblib.c
@@ -707,7 +707,7 @@ static void set_convenience_ptr(smbmsg_t* msg, ushort hfield_type, void* hfield_
 			msg->from=(char*)hfield_dat;
 			break; 
 		case SENDER:
-			if(!msg->from) {
+			if(msg->from==NULL || *(msg->from)==0) {
 				msg->from=(char*)hfield_dat;
 				break; 
 			}