diff --git a/stl/inc/yvals.h b/stl/inc/yvals.h
index 8702c037e2a..18808df45e4 100644
--- a/stl/inc/yvals.h
+++ b/stl/inc/yvals.h
@@ -275,14 +275,6 @@ _EMIT_STL_WARNING(STL4001, "/clr:pure is deprecated and will be REMOVED.");
 #endif
 #endif // _CRTIMP2_PURE
 
-#ifdef _CRTBLD
-// These functions are for enabling STATIC_CPPLIB functionality
-#define _cpp_stdin         (__acrt_iob_func(0))
-#define _cpp_stdout        (__acrt_iob_func(1))
-#define _cpp_stderr        (__acrt_iob_func(2))
-#define _cpp_isleadbyte(c) (__pctype_func()[static_cast<unsigned char>(c)] & _LEADBYTE)
-#endif // defined(_CRTBLD)
-
 #ifndef _CRTIMP2_IMPORT
 #if defined(CRTDLL2) && defined(_CRTBLD)
 #define _CRTIMP2_IMPORT __declspec(dllexport)
diff --git a/stl/src/_tolower.cpp b/stl/src/_tolower.cpp
index 16bec174d3d..2f342bcc365 100644
--- a/stl/src/_tolower.cpp
+++ b/stl/src/_tolower.cpp
@@ -17,6 +17,8 @@
 #undef _tolower
 #undef tolower
 
+#define _cpp_isleadbyte(c) (__pctype_func()[static_cast<unsigned char>(c)] & _LEADBYTE)
+
 _EXTERN_C_UNLESS_PURE
 
 // int _Tolower(c) - convert character to lower case
diff --git a/stl/src/_toupper.cpp b/stl/src/_toupper.cpp
index 70ef52d7c77..fcf5686f848 100644
--- a/stl/src/_toupper.cpp
+++ b/stl/src/_toupper.cpp
@@ -16,6 +16,8 @@
 #undef _toupper
 #undef toupper
 
+#define _cpp_isleadbyte(c) (__pctype_func()[static_cast<unsigned char>(c)] & _LEADBYTE)
+
 _EXTERN_C_UNLESS_PURE
 
 // int _Toupper(c) - convert character to uppercase
diff --git a/stl/src/cerr.cpp b/stl/src/cerr.cpp
index a8db79602ce..3a5f23ce49d 100644
--- a/stl/src/cerr.cpp
+++ b/stl/src/cerr.cpp
@@ -14,7 +14,7 @@ static std::_Init_locks initlocks;
 
 _STD_BEGIN
 
-__PURE_APPDOMAIN_GLOBAL static filebuf ferr(_cpp_stderr);
+__PURE_APPDOMAIN_GLOBAL static filebuf ferr(stderr);
 
 #if defined(_M_CEE_PURE)
 __PURE_APPDOMAIN_GLOBAL extern ostream cerr(&ferr);
diff --git a/stl/src/cin.cpp b/stl/src/cin.cpp
index 68fec6a6e55..6c7b4679817 100644
--- a/stl/src/cin.cpp
+++ b/stl/src/cin.cpp
@@ -14,7 +14,7 @@ static std::_Init_locks initlocks;
 
 _STD_BEGIN
 
-__PURE_APPDOMAIN_GLOBAL static filebuf fin(_cpp_stdin);
+__PURE_APPDOMAIN_GLOBAL static filebuf fin(stdin);
 
 #if defined(_M_CEE_PURE)
 __PURE_APPDOMAIN_GLOBAL extern istream cin(&fin);
diff --git a/stl/src/clog.cpp b/stl/src/clog.cpp
index 6ae37572e27..e29b72ec85c 100644
--- a/stl/src/clog.cpp
+++ b/stl/src/clog.cpp
@@ -16,7 +16,7 @@ static std::_Init_locks initlocks;
 
 _STD_BEGIN
 
-__PURE_APPDOMAIN_GLOBAL static filebuf flog(_cpp_stderr);
+__PURE_APPDOMAIN_GLOBAL static filebuf flog(stderr);
 
 #if defined(_M_CEE_PURE)
 __PURE_APPDOMAIN_GLOBAL extern ostream clog(&flog);
diff --git a/stl/src/cout.cpp b/stl/src/cout.cpp
index 60f8445c732..02ab1f7eb27 100644
--- a/stl/src/cout.cpp
+++ b/stl/src/cout.cpp
@@ -14,7 +14,7 @@ static std::_Init_locks initlocks;
 
 _STD_BEGIN
 
-__PURE_APPDOMAIN_GLOBAL static filebuf fout(_cpp_stdout);
+__PURE_APPDOMAIN_GLOBAL static filebuf fout(stdout);
 
 #if defined(_M_CEE_PURE)
 __PURE_APPDOMAIN_GLOBAL extern ostream cout(&fout);
diff --git a/stl/src/wcerr.cpp b/stl/src/wcerr.cpp
index c2ff56b6ec8..41537b600b8 100644
--- a/stl/src/wcerr.cpp
+++ b/stl/src/wcerr.cpp
@@ -14,7 +14,7 @@ static std::_Init_locks initlocks;
 
 _STD_BEGIN
 
-__PURE_APPDOMAIN_GLOBAL static wfilebuf wferr(_cpp_stderr);
+__PURE_APPDOMAIN_GLOBAL static wfilebuf wferr(stderr);
 #if defined(_M_CEE_PURE)
 __PURE_APPDOMAIN_GLOBAL extern wostream wcerr(&wferr);
 #else
diff --git a/stl/src/wcin.cpp b/stl/src/wcin.cpp
index f5c7a1a5e70..bc5008776d9 100644
--- a/stl/src/wcin.cpp
+++ b/stl/src/wcin.cpp
@@ -14,7 +14,7 @@ static std::_Init_locks initlocks;
 
 _STD_BEGIN
 
-__PURE_APPDOMAIN_GLOBAL static wfilebuf wfin(_cpp_stdin);
+__PURE_APPDOMAIN_GLOBAL static wfilebuf wfin(stdin);
 #if defined(_M_CEE_PURE)
 __PURE_APPDOMAIN_GLOBAL extern wistream wcin(&wfin);
 #else
diff --git a/stl/src/wclog.cpp b/stl/src/wclog.cpp
index 513f7b9105a..3ac05b10172 100644
--- a/stl/src/wclog.cpp
+++ b/stl/src/wclog.cpp
@@ -14,7 +14,7 @@ static std::_Init_locks initlocks;
 
 _STD_BEGIN
 
-__PURE_APPDOMAIN_GLOBAL static wfilebuf wflog(_cpp_stderr);
+__PURE_APPDOMAIN_GLOBAL static wfilebuf wflog(stderr);
 #if defined(_M_CEE_PURE)
 __PURE_APPDOMAIN_GLOBAL extern wostream wclog(&wflog);
 #else
diff --git a/stl/src/wcout.cpp b/stl/src/wcout.cpp
index fc574d689c3..c9693987eb9 100644
--- a/stl/src/wcout.cpp
+++ b/stl/src/wcout.cpp
@@ -14,7 +14,7 @@ static std::_Init_locks initlocks;
 
 _STD_BEGIN
 
-__PURE_APPDOMAIN_GLOBAL static wfilebuf wfout(_cpp_stdout);
+__PURE_APPDOMAIN_GLOBAL static wfilebuf wfout(stdout);
 #if defined(_M_CEE_PURE)
 __PURE_APPDOMAIN_GLOBAL extern wostream wcout(&wfout);
 #else