diff --git a/src/make.tcl b/src/make.tcl
index dbf6d7f9..c469fc4f 100644
--- a/src/make.tcl
+++ b/src/make.tcl
@@ -60,6 +60,11 @@ if {[llength $runtimes] > 1} {
 }
 
 set runtimefile [lindex $runtimes 0]
+#sdx *may* be pointed to use the runtime we use to build the kit, or the user may manually use this runtime if they don't have tclsh
+#sdx will complain if the same runtime is used for the shell as is used in the -runtime argument - so we make a copy (REVIEW)
+if {![file exists $sourcefolder/_build/buildruntime.exe]} {
+    file copy $rtfolder/$runtimefile $sourcefolder/_build/buildruntime.exe
+}
 
 puts stdout "Found [llength $vfs_folders] .vfs folders - building executable for each..."
 foreach vfs $vfs_folders {
@@ -72,12 +77,12 @@ foreach vfs $vfs_folders {
         file delete $sourcefolder/_build/$vfsname
     }
 
-    puts stdout "building $vfsname with sdx.."
+    puts stdout "building $vfsname with sdx.. vfsdir:$vfs cwd: [pwd]"
     
     if {[catch {
-        exec sdx wrap _build/$vfsname -runtime runtime/$runtimefile -verbose
+        exec sdx wrap [pwd]/_build/$vfsname -vfs [pwd]/$vfs -runtime $sourcefolder/_build/buildruntime.exe -verbose
         } result]} {
-        puts stderr "sdx wrap _build/$vfsname -runtime runtime/$runtimefile -verbose failed with msg: $result"
+        puts stderr "sdx wrap _build/$vfsname -vfs [pwd]/$vfs -runtime $sourcefolder/_build/buildruntime.exe -verbose failed with msg: $result"
     } else {
         puts stdout "ok - finished sdx"
         set separator [string repeat = 40]