diff --git a/Changes.md b/Changes.md
index 2720a0f40..453ea6c7e 100644
--- a/Changes.md
+++ b/Changes.md
@@ -1,5 +1,18 @@
 # Build System Changes for Android.mk Writers
 
+## ELF prebuilts in PRODUCT_COPY_FILES
+
+ELF prebuilts in PRODUCT_COPY_FILES that are installed into these paths are an
+error:
+
+* `<partition>/bin/*`
+* `<partition>/lib/*`
+* `<partition>/lib64/*`
+
+Define prebuilt modules and add them to PRODUCT_PACKAGES instead.
+To temporarily relax this check and restore the behavior prior to this change,
+set `BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES := true` in `BoardConfig.mk`.
+
 ## COPY_HEADERS usage now produces warnings {#copy_headers}
 
 We've considered `BUILD_COPY_HEADERS`/`LOCAL_COPY_HEADERS` to be deprecated for
diff --git a/core/Makefile b/core/Makefile
index 29a6beacb..835ae5f82 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -40,11 +40,9 @@ $(if $(filter true,$(BUILD_BROKEN_VINTF_PRODUCT_COPY_FILES)),, \
 )
 endef
 
-# TODO(b/140560012): Flip BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES to default
-# false after all problematic devices are tagged.
-check_elf_prebuilt_product_copy_files :=
-ifneq (,$(filter false,$(BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES)))
 check_elf_prebuilt_product_copy_files := true
+ifneq (,$(filter true,$(BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES)))
+check_elf_prebuilt_product_copy_files :=
 endif
 check_elf_prebuilt_product_copy_files_hint := \
     found ELF prebuilt in PRODUCT_COPY_FILES, use cc_prebuilt_binary / cc_prebuilt_library_shared instead.