diff --git a/core/dex_preopt.mk b/core/dex_preopt.mk
index 6499b63..e0dde01 100644
--- a/core/dex_preopt.mk
+++ b/core/dex_preopt.mk
@@ -19,13 +19,6 @@
 # The default value for LOCAL_DEX_PREOPT
 DEX_PREOPT_DEFAULT ?= true
 
-# The default values for pre-opting: always preopt PIC.
-# Conditional to building on linux, as dex2oat currently does not work on darwin.
-ifeq ($(HOST_OS),linux)
-  WITH_DEXPREOPT_PIC ?= true
-  WITH_DEXPREOPT ?= true
-endif
-
 # $(1): the .jar or .apk to remove classes.dex
 define dexpreopt-remove-classes.dex
 $(hide) zip --quiet --delete $(1) classes.dex; \
diff --git a/core/main.mk b/core/main.mk
index 211e06a..aa6d15f 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -368,6 +368,18 @@
     enable_target_debugging :=
   endif
 
+  # Turn on Dalvik preoptimization for user builds, but only if not
+  # explicitly disabled and the build is running on Linux (since host
+  # Dalvik isn't built for non-Linux hosts).
+  ifeq (,$(WITH_DEXPREOPT))
+    ifeq ($(user_variant),user)
+      ifeq ($(HOST_OS),linux)
+        # TODO: turn on WITH_DEXPREOPT for libart user builds.
+        # WITH_DEXPREOPT := true
+      endif
+    endif
+  endif
+
   # Disallow mock locations by default for user builds
   ADDITIONAL_DEFAULT_PROPERTIES += ro.allow.mock.location=0
 
@@ -403,8 +415,10 @@
           ro.setupwizard.mode=OPTIONAL
 endif
 ifndef is_sdk_build
-  # To speedup startup of non-preopted builds, don't verify or compile the boot image.
+  # Don't verify or compile the image on eng builds to speed startup.
   ADDITIONAL_BUILD_PROPERTIES += dalvik.vm.image-dex2oat-filter=verify-at-runtime
+  # Don't verify or compile apps on eng builds to speed startup.
+  ADDITIONAL_BUILD_PROPERTIES += dalvik.vm.dex2oat-filter=verify-at-runtime
 endif
 endif