diff --git a/build.sh b/build.sh
index 9e1ebf2149511fe4daca2a9a0a572dbdcd955635..b66d1a070571e65df97f876f336dec19785586a3 100755
--- a/build.sh
+++ b/build.sh
@@ -216,6 +216,8 @@ fi
 # Check to see if we're skipping the platform
 eval '$build_'"$arch" || pass
 
+# ensure AUTOBUILD is in native path form for child processes
+AUTOBUILD="$(native_path "$AUTOBUILD")"
 # set "$autobuild" to cygwin path form for use locally in this script
 autobuild="$(shell_path "$AUTOBUILD")"
 if [ ! -x "$autobuild" ]