Index: generic/nsf.c
===================================================================
diff -u -r462bf8f1d53c0f2bcaa795f542e2f65cdab996b5 -rbc7f267ac8f8439d87c710917eabcd6f65f22816
--- generic/nsf.c	(.../nsf.c)	(revision 462bf8f1d53c0f2bcaa795f542e2f65cdab996b5)
+++ generic/nsf.c	(.../nsf.c)	(revision bc7f267ac8f8439d87c710917eabcd6f65f22816)
@@ -20786,7 +20786,7 @@
       }
       goto add_to_freelist;
 
-    } else if (c == '1' && (c1 == '\0' || c1 == ' ')) {
+    } else if (c == '1' && (c1 == '\0' || NsfHasTclSpace(&c1))) {
 
       if (c1 != '\0') {
         if (unlikely(Tcl_ListObjIndex(interp, forwardArgObj, 1, &list) != TCL_OK)) {
Index: tests/forward.test
===================================================================
diff -u -r275da34d3d7a874a451eced58242b738c8a37d1a -rbc7f267ac8f8439d87c710917eabcd6f65f22816
--- tests/forward.test	(.../forward.test)	(revision 275da34d3d7a874a451eced58242b738c8a37d1a)
+++ tests/forward.test	(.../forward.test)	(revision bc7f267ac8f8439d87c710917eabcd6f65f22816)
@@ -318,6 +318,10 @@
   obj public object forward foo -verbose %self {%1 {FOO OOF}} {%1 {A B}}
   ? {obj foo X} "OOF-B X"
 
+  obj public object forward foo -verbose %self "%1\n{FOO\nOOF}" "%1\r{A\tB}"
+  ? {obj foo X} "OOF-B X"
+
+
   ##
   ## -prefix; requires a 2nd arg!
   ##