diff --git a/libc/bionic/__libc_init_main_thread.cpp b/libc/bionic/__libc_init_main_thread.cpp
index 9cbff11..d7581dd 100644
--- a/libc/bionic/__libc_init_main_thread.cpp
+++ b/libc/bionic/__libc_init_main_thread.cpp
@@ -31,6 +31,7 @@
 #include "private/KernelArgumentBlock.h"
 #include "private/bionic_arc4random.h"
 #include "private/bionic_auxv.h"
+#include "private/bionic_defs.h"
 #include "private/bionic_globals.h"
 #include "private/bionic_ssp.h"
 #include "pthread_internal.h"
@@ -58,6 +59,7 @@
 // -fno-stack-protector because it's responsible for setting up the main
 // thread's TLS (which stack protector relies on).
 
+__BIONIC_WEAK_FOR_NATIVE_BRIDGE
 void __libc_init_main_thread(KernelArgumentBlock& args) {
   __libc_auxv = args.auxv;
 #if defined(__i386__)
diff --git a/libc/bionic/android_set_abort_message.cpp b/libc/bionic/android_set_abort_message.cpp
index 8c80c5a..268c4f3 100644
--- a/libc/bionic/android_set_abort_message.cpp
+++ b/libc/bionic/android_set_abort_message.cpp
@@ -32,6 +32,7 @@
 #include <string.h>
 #include <sys/mman.h>
 
+#include "private/bionic_defs.h"
 #include "private/ScopedPthreadMutexLocker.h"
 
 static pthread_mutex_t g_abort_msg_lock = PTHREAD_MUTEX_INITIALIZER;
@@ -43,6 +44,7 @@
 
 abort_msg_t** __abort_message_ptr; // Accessible to __libc_init_common.
 
+__BIONIC_WEAK_FOR_NATIVE_BRIDGE
 void android_set_abort_message(const char* msg) {
   ScopedPthreadMutexLocker locker(&g_abort_msg_lock);
 
diff --git a/libc/private/bionic_defs.h b/libc/private/bionic_defs.h
new file mode 100644
index 0000000..d9e016c
--- /dev/null
+++ b/libc/private/bionic_defs.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef __BIONIC_PRIVATE_BIONIC_DEFS_H_
+#define __BIONIC_PRIVATE_BIONIC_DEFS_H_
+
+/*
+ * This label is used to mark libc/libdl symbols that may need to be replaced
+ * by native bridge implementation.
+ */
+#define __BIONIC_WEAK_FOR_NATIVE_BRIDGE __attribute__((__weak__, __noinline__))
+
+#endif /* __BIONIC_PRIVATE_BIONIC_DEFS_H_ */