diff --git a/include/msvcrt/float.h b/include/msvcrt/float.h
index 270e1756269..33ebb689eec 100644
--- a/include/msvcrt/float.h
+++ b/include/msvcrt/float.h
@@ -128,6 +128,16 @@ extern "C" {
 #define _FPE_STACKUNDERFLOW     0x8b
 #define _FPE_EXPLICITGEN        0x8c
 
+#if defined(__i386__)
+#define _CW_DEFAULT (_RC_NEAR + _PC_53 + _EM_INVALID + _EM_ZERODIVIDE + _EM_OVERFLOW + _EM_UNDERFLOW + _EM_INEXACT + _EM_DENORMAL)
+#elif defined(__x86_64__)
+#define _CW_DEFAULT (_RC_NEAR + _PC_64 + _EM_INVALID + _EM_ZERODIVIDE + _EM_OVERFLOW + _EM_UNDERFLOW + _EM_INEXACT + _EM_DENORMAL)
+#endif
+
+unsigned int __cdecl _control87(unsigned int, unsigned int);
+unsigned int __cdecl _controlfp(unsigned int, unsigned int);
+errno_t __cdecl _controlfp_s(unsigned int *, unsigned int, unsigned int);
+
 double __cdecl _copysign (double, double);
 double __cdecl _chgsign (double);
 double __cdecl _scalb(double, __msvcrt_long);