diff --git a/libc/include/android/api-level.h b/libc/include/android/api-level.h
index bcddddd..40846fb 100644
--- a/libc/include/android/api-level.h
+++ b/libc/include/android/api-level.h
@@ -151,6 +151,9 @@
 /** Names the "S" API level (31), for comparison against `__ANDROID_API__`. */
 #define __ANDROID_API_S__ 31
 
+/* This file is included in <features.h>, and might be used from .S files. */
+#if !defined(__ASSEMBLY__)
+
 /**
  * Returns the `targetSdkVersion` of the caller, or `__ANDROID_API_FUTURE__` if
  * there is no known target SDK version (for code not running in the context of
@@ -167,7 +170,7 @@
 
 #if __ANDROID_API__ < 29
 
-// android_get_device_api_level is a static inline before API level 29.
+/* android_get_device_api_level is a static inline before API level 29. */
 #define __BIONIC_GET_DEVICE_API_LEVEL_INLINE static __inline
 #include <bits/get_device_api_level_inlines.h>
 #undef __BIONIC_GET_DEVICE_API_LEVEL_INLINE
@@ -185,6 +188,8 @@
 
 #endif
 
+#endif /* defined(__ASSEMBLY__) */
+
 __END_DECLS
 
 /** @} */
diff --git a/libc/private/bionic_asm.h b/libc/private/bionic_asm.h
index 6d4f7d5..d68a2d6 100644
--- a/libc/private/bionic_asm.h
+++ b/libc/private/bionic_asm.h
@@ -26,8 +26,10 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _PRIVATE_BIONIC_ASM_H_
-#define _PRIVATE_BIONIC_ASM_H_
+#pragma once
+
+/* https://github.com/android/ndk/issues/1422 */
+#include <features.h>
 
 #include <asm/unistd.h> /* For system call numbers. */
 #define MAX_ERRNO 4095  /* For recognizing system call error returns. */
@@ -86,5 +88,3 @@
 
 #define NOTE_GNU_PROPERTY() \
     __bionic_asm_custom_note_gnu_section()
-
-#endif