diff --git a/libc/Android.mk b/libc/Android.mk
index 8085ac5..364f4ca 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -500,10 +500,13 @@
 libc_common_cflags := \
     -DWITH_ERRLIST \
     -DANDROID_CHANGES \
+    -DUSE_LOCKS \
+    -DREALLOC_ZERO_BYTES_FREES \
     -D_LIBC=1 \
     -DFLOATING_POINT \
     -DINET6 \
     -I$(LOCAL_PATH)/private \
+    -DUSE_DL_PREFIX \
     -DPOSIX_MISTAKE \
     -DLOG_ON_HEAP_ERROR \
     -std=gnu99