diff --git a/target/product/base_system.mk b/target/product/base_system.mk
index a728068..87076a9 100644
--- a/target/product/base_system.mk
+++ b/target/product/base_system.mk
@@ -329,7 +329,8 @@
 
 # Add the compatibility library that is needed when android.test.base
 # is removed from the bootclasspath.
-ifeq ($(REMOVE_ATB_FROM_BCP),true)
+# Default to excluding android.test.base from the bootclasspath.
+ifneq ($(REMOVE_ATB_FROM_BCP),false)
 PRODUCT_PACKAGES += framework-atb-backward-compatibility
 PRODUCT_BOOT_JARS += framework-atb-backward-compatibility
 else