diff --git a/distrib/scripts/manifests/mgl.rsp b/distrib/scripts/manifests/mgl.rsp
index ba95940fc9..997a9d5c6b 100644
--- a/distrib/scripts/manifests/mgl.rsp
+++ b/distrib/scripts/manifests/mgl.rsp
@@ -1,3 +1,5 @@
+build/mgl/*
+
 include/wx/mgl/*.h
 src/mgl/*.cpp
 src/mgl/*.lst
diff --git a/distrib/scripts/manifests/os2.rsp b/distrib/scripts/manifests/os2.rsp
index c85156272a..481fd26b74 100644
--- a/distrib/scripts/manifests/os2.rsp
+++ b/distrib/scripts/manifests/os2.rsp
@@ -1,5 +1,7 @@
 lib/dummy
 
+build/os2/*
+
 docs/licence.txt
 docs/os2/*.txt
 
diff --git a/distrib/scripts/pre-flight.sh b/distrib/scripts/pre-flight.sh
index c728d9cfbb..f6de238e41 100755
--- a/distrib/scripts/pre-flight.sh
+++ b/distrib/scripts/pre-flight.sh
@@ -44,6 +44,9 @@ fi
 if [ $rebake = "yes" ]; then
   cd $WX_SRC_DIR/build/bakefiles
   bakefile_gen -d ../../distrib/scripts/Bakefiles.release.bkgen
+  bakefile_gen -f watcom
+  bakefile_gen -f watcom -d ../mgl/Bakefiles.mgl.bkgen
+  bakefile_gen -f watcom -d ../os2/Bakefiles.os2.bkgen
 fi
 
 cd $WX_SRC_DIR