diff --git a/Android.mk b/Android.mk
index 173b983..11a693d 100644
--- a/Android.mk
+++ b/Android.mk
@@ -177,7 +177,7 @@
 endif
 
 # Library extension for host-side tests
-ifeq ($(HOSTOS),darwin)
+ifeq ($(HOST_OS),darwin)
 SHAREDLIB_EXT=dylib
 else
 SHAREDLIB_EXT=so
diff --git a/public/domain.te b/public/domain.te
index 9bc9e4e..f28da11 100644
--- a/public/domain.te
+++ b/public/domain.te
@@ -481,10 +481,10 @@
   { append link rename write open read ioctl lock };
 
 # No domain other than recovery and update_engine can write to system partition(s).
-neverallow { domain -recovery -update_engine } system_block_device:blk_file write;
+neverallow { domain -recovery -update_engine } system_block_device:blk_file { write append };
 
 # No domains other than install_recovery or recovery can write to recovery.
-neverallow { domain -install_recovery -recovery } recovery_block_device:blk_file write;
+neverallow { domain -install_recovery -recovery } recovery_block_device:blk_file { write append };
 
 # No domains other than a select few can access the misc_block_device. This
 # block device is reserved for OTA use.