diff --git a/libc/include/fenv.h b/libc/include/fenv.h
index 3fd9852..5f15ff3 100644
--- a/libc/include/fenv.h
+++ b/libc/include/fenv.h
@@ -46,18 +46,18 @@
 // fenv was always available on x86.
 #if __ANDROID_API__ >= 21 || defined(__i386__)
 int feclearexcept(int __exceptions) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
-int fegetexceptflag(fexcept_t* __flag_ptr, int __exceptions) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
+int fegetexceptflag(fexcept_t* _Nonnull __flag_ptr, int __exceptions) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
 int feraiseexcept(int __exceptions) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
-int fesetexceptflag(const fexcept_t* __flag_ptr, int __exceptions) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
+int fesetexceptflag(const fexcept_t* _Nonnull __flag_ptr, int __exceptions) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
 int fetestexcept(int __exceptions) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
 
 int fegetround(void) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
 int fesetround(int __rounding_mode) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
 
-int fegetenv(fenv_t* __env) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
-int feholdexcept(fenv_t* __env) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
-int fesetenv(const fenv_t* __env) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
-int feupdateenv(const fenv_t* __env) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
+int fegetenv(fenv_t* _Nonnull __env) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
+int feholdexcept(fenv_t* _Nonnull __env) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
+int fesetenv(const fenv_t* _Nonnull __env) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
+int feupdateenv(const fenv_t* _Nonnull __env) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
 
 int feenableexcept(int __exceptions) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);
 int fedisableexcept(int __exceptions) __INTRODUCED_IN_ARM(21) __INTRODUCED_IN_X86(9);