diff -uNr debian.orig/rules debian/rules
--- debian.orig/rules	2020-10-29 11:10:15.729447648 +0100
+++ debian/rules	2020-10-29 11:11:17.473449120 +0100
@@ -414,7 +414,7 @@
 endif
 
 ifneq (,$(filter $(DEB_HOST_ARCH), amd64))
-  DEFAULT_CONFIGURE_ARGS += --with-jvm-features=zgc
+  DEFAULT_CONFIGURE_ARGS += --with-jvm-features=shenandoahgc,zgc
 endif
 
 ifeq ($(distribution),Debian)