diff --git a/core/board_config.mk b/core/board_config.mk
index 1e0e9e1..528c133 100644
--- a/core/board_config.mk
+++ b/core/board_config.mk
@@ -19,6 +19,11 @@
 # and sanity-checks the variable defined therein.
 # ###############################################################
 
+# Conditional to building on linux, as dex2oat currently does not work on darwin.
+ifeq ($(HOST_OS),linux)
+  WITH_DEXPREOPT := true
+endif
+
 # ###############################################################
 # Broken build defaults
 # ###############################################################
diff --git a/core/dex_preopt_config.mk b/core/dex_preopt_config.mk
index 9bf2be8..13e4634 100644
--- a/core/dex_preopt_config.mk
+++ b/core/dex_preopt_config.mk
@@ -20,7 +20,6 @@
 endif
 # Conditional to building on linux, as dex2oat currently does not work on darwin.
 ifeq ($(HOST_OS),linux)
-  WITH_DEXPREOPT ?= true
   ifeq (eng,$(TARGET_BUILD_VARIANT))
     # Don't strip for quick development turnarounds.
     DEX_PREOPT_DEFAULT := nostripping