diff --git a/src/make.tcl b/src/make.tcl
index 8ee0b062..8402c0b1 100644
--- a/src/make.tcl
+++ b/src/make.tcl
@@ -2899,11 +2899,14 @@ foreach vfstail $vfs_tails {
                             #tcl we are calling with doesn't have zipfs - can't mount
                             puts stderr "WARNING: tcl shell '[info nameofexecutable]' being used to build doesn't have zipfs - falling back to punk::zip::extract_preamble"
                             set extractedzip $buildfolder/extracted_$runtime_fullname.zip
+                            file delete $raw_runtime
+                            file delete $extractedzip
+                            file delete -force $buildfolder/extracted_$runtime_fullname
                             punk::zip::extract_preamble $building_runtime $raw_runtime $extractedzip
                             package require zipfile::decode
-                            zipfile::open $extractedzip
-                            set archiveinfo [zipfile::archive]
-                            zipfile::unzip $archiveinfo extracted_$runtime_fullname
+                            zipfile::decode::open $extractedzip
+                            set archiveinfo [zipfile::decode::archive]
+                            zipfile::decode::unzip $archiveinfo extracted_$runtime_fullname
                             #todo - verify that init.tcl etc are present?
                             merge_over $buildfolder/extracted_$runtime_fullname $targetvfs
                         }