diff --git a/libc/include/assert.h b/libc/include/assert.h
index dea8382..8c456ef 100644
--- a/libc/include/assert.h
+++ b/libc/include/assert.h
@@ -1,6 +1,3 @@
-/*	$OpenBSD: assert.h,v 1.12 2006/01/31 10:53:51 hshoexer Exp $	*/
-/*	$NetBSD: assert.h,v 1.6 1994/10/26 00:55:44 cgd Exp $	*/
-
 /*-
  * Copyright (c) 1992, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -33,34 +30,33 @@
  * 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.
- *
- *	@(#)assert.h	8.2 (Berkeley) 1/21/94
  */
 
 /*
- * Unlike other ANSI header files, <assert.h> may usefully be included
- * multiple times, with and without NDEBUG defined.
+ * There's no include guard in this file because <assert.h> may usefully be
+ * included multiple times, with and without NDEBUG defined.
  */
 
 #include <sys/cdefs.h>
 
 #undef assert
-#undef _assert
+#undef __assert_no_op
+
+#define __assert_no_op __BIONIC_CAST(static_cast, void, 0)
 
 #ifdef NDEBUG
-# define	assert(e)	((void)0)
-# define	_assert(e)	((void)0)
+# define assert(e) __assert_no_op
 #else
-# define	_assert(e)	assert(e)
-# if __STDC_VERSION__ >= 199901L
-#  define	assert(e)	((e) ? (void)0 : __assert2(__FILE__, __LINE__, __func__, #e))
+# if defined(__cplusplus) || __STDC_VERSION__ >= 199901L
+#  define assert(e) ((e) ? __assert_no_op : __assert2(__FILE__, __LINE__, __PRETTY_FUNCTION__, #e))
 # else
-#  define	assert(e)	((e) ? (void)0 : __assert(__FILE__, __LINE__, #e))
+#  define assert(e) ((e) ? __assert_no_op : __assert(__FILE__, __LINE__, #e))
 # endif
 #endif
 
 #if !defined(__cplusplus) && __STDC_VERSION__ >= 201112L
-#define static_assert _Static_assert
+# undef static_assert
+# define static_assert _Static_assert
 #endif
 
 __BEGIN_DECLS
diff --git a/libc/include/stdio.h b/libc/include/stdio.h
index c876b0f..c2f6d84 100644
--- a/libc/include/stdio.h
+++ b/libc/include/stdio.h
@@ -149,7 +149,8 @@
 int dprintf(int, const char* __restrict _Nonnull, ...) __printflike(2, 3) __INTRODUCED_IN(21);
 int vdprintf(int, const char* __restrict _Nonnull, __va_list) __printflike(2, 0) __INTRODUCED_IN(21);
 
-#if __STDC_VERSION__ < 201112L
+#if (defined(__STDC_VERSION__) && __STDC_VERSION__ < 201112L) || \
+    (defined(__cplusplus) && __cplusplus <= 201103L)
 char* gets(char*) __attribute__((deprecated("gets is unsafe, use fgets instead")));
 #endif
 int sprintf(char* __restrict, const char* __restrict _Nonnull, ...) __printflike(2, 3);
diff --git a/libc/include/sys/cdefs.h b/libc/include/sys/cdefs.h
index e44ba52..eb8ff21 100644
--- a/libc/include/sys/cdefs.h
+++ b/libc/include/sys/cdefs.h
@@ -229,16 +229,6 @@
 #endif
 #endif
 
-/* C99 added the `restrict` type qualifier keyword. Before then, `__restrict` is a GNU extension. */
-#if __STDC_VERSION__ >= 199901L
-#define __restrict restrict
-#endif
-
-/* C99 added the `__func__` predefined identifier. */
-#if __STDC_VERSION__ < 199901L
-#define __func__ __PRETTY_FUNCTION__
-#endif
-
 #define  __BIONIC__   1
 #include <android/api-level.h>