diff --git a/libc/arch-common/bionic/crtbegin.c b/libc/arch-common/bionic/crtbegin.c
index 45c9ea707..0921f4faf 100644
--- a/libc/arch-common/bionic/crtbegin.c
+++ b/libc/arch-common/bionic/crtbegin.c
@@ -36,7 +36,7 @@ SECTION(".init_array") void (*__INIT_ARRAY__)(void) = (void (*)(void)) -1;
 SECTION(".fini_array") void (*__FINI_ARRAY__)(void) = (void (*)(void)) -1;
 #undef SECTION
 
-static void _start_main(void* raw_args) __used {
+__used static void _start_main(void* raw_args) {
   structors_array_t array;
   array.preinit_array = &__PREINIT_ARRAY__;
   array.init_array = &__INIT_ARRAY__;
diff --git a/libc/arch-common/bionic/pthread_atfork.h b/libc/arch-common/bionic/pthread_atfork.h
index 0c48a1269..c6a33ffe0 100644
--- a/libc/arch-common/bionic/pthread_atfork.h
+++ b/libc/arch-common/bionic/pthread_atfork.h
@@ -14,6 +14,12 @@
  * limitations under the License.
  */
 
+#include <android/api-level.h>
+
+// __register_atfork wasn't available until android-23. We need to build a
+// pre-23 and 23+ version of crtbegin.
+#if __ANDROID_API__ >= __ANDROID_API_M__
+
 extern void* __dso_handle;
 
 extern int __register_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void), void* dso);
@@ -27,3 +33,4 @@ int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(vo
   return __register_atfork(prepare, parent, child, &__dso_handle);
 }
 
+#endif  /* __ANDROID_API__ >= __ANDROID_API_M__ */