diff --git a/stl/inc/xthreads.h b/stl/inc/xthreads.h
index 26302f0aea3..7f78cec33f9 100644
--- a/stl/inc/xthreads.h
+++ b/stl/inc/xthreads.h
@@ -107,11 +107,6 @@ _CRTIMP2_PURE _Thrd_result __cdecl _Mtx_lock(_Mtx_t);
 _CRTIMP2_PURE _Thrd_result __cdecl _Mtx_trylock(_Mtx_t);
 _CRTIMP2_PURE _Thrd_result __cdecl _Mtx_unlock(_Mtx_t); // TRANSITION, ABI: Always succeeds
 
-#ifdef _CRTBLD
-_CRTIMP2_PURE void __cdecl _Mtx_clear_owner(_Mtx_t);
-_CRTIMP2_PURE void __cdecl _Mtx_reset_owner(_Mtx_t);
-#endif // _CRTBLD
-
 // shared mutex
 // these declarations must be in sync with those in sharedmutex.cpp
 void __cdecl _Smtx_lock_exclusive(_Smtx_t*);
diff --git a/stl/inc/yvals.h b/stl/inc/yvals.h
index 8702c037e2a..9f337dad050 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)
@@ -449,19 +441,6 @@ class _CRTIMP2_PURE_IMPORT _EmptyLockit { // empty lock class used for bin compa
 #define _END_LOCINFO() }
 #endif // ^^^ !defined(_M_CEE) ^^^
 
-#ifdef _CRTBLD
-
-#ifdef _M_CEE
-#define _RELIABILITY_CONTRACT                                                    \
-    [System::Runtime::ConstrainedExecution::ReliabilityContract(                 \
-        System::Runtime::ConstrainedExecution::Consistency::WillNotCorruptState, \
-        System::Runtime::ConstrainedExecution::Cer::Success)]
-#else // ^^^ defined(_M_CEE) / !defined(_M_CEE) vvv
-#define _RELIABILITY_CONTRACT
-#endif // ^^^ !defined(_M_CEE) ^^^
-
-#endif // defined(_CRTBLD)
-
 #if _HAS_EXCEPTIONS
 #define _TRY_BEGIN try {
 #define _CATCH(x) \
diff --git a/stl/src/awint.hpp b/stl/src/awint.hpp
index acb1667e736..24052ffefa4 100644
--- a/stl/src/awint.hpp
+++ b/stl/src/awint.hpp
@@ -10,6 +10,8 @@
 
 #include <Windows.h>
 
+#define _cpp_isleadbyte(c) (__pctype_func()[static_cast<unsigned char>(c)] & _LEADBYTE)
+
 _CRT_BEGIN_C_HEADER
 
 #if _STL_WIN32_WINNT >= _WIN32_WINNT_WIN8
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/cond.cpp b/stl/src/cond.cpp
index 01d964ef6f3..fa094b04407 100644
--- a/stl/src/cond.cpp
+++ b/stl/src/cond.cpp
@@ -48,6 +48,18 @@ _CRTIMP2_PURE void __cdecl _Cnd_destroy(const _Cnd_t cond) { // clean up
     }
 }
 
+// TRANSITION, ABI: should be static; dllexported for binary compatibility
+_CRTIMP2_PURE void __cdecl _Mtx_clear_owner(_Mtx_t mtx) { // set owner to nobody
+    mtx->_Thread_id = -1;
+    --mtx->_Count;
+}
+
+// TRANSITION, ABI: should be static; dllexported for binary compatibility
+_CRTIMP2_PURE void __cdecl _Mtx_reset_owner(_Mtx_t mtx) { // set owner to current thread
+    mtx->_Thread_id = static_cast<long>(GetCurrentThreadId());
+    ++mtx->_Count;
+}
+
 _CRTIMP2_PURE _Thrd_result __cdecl _Cnd_wait(const _Cnd_t cond, const _Mtx_t mtx) { // wait until signaled
     const auto cs = &mtx->_Critical_section;
     _Mtx_clear_owner(mtx);
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/mutex.cpp b/stl/src/mutex.cpp
index ba8c2de344f..98cf98d1cdf 100644
--- a/stl/src/mutex.cpp
+++ b/stl/src/mutex.cpp
@@ -189,16 +189,6 @@ _CRTIMP2_PURE void* __cdecl _Mtx_getconcrtcs(_Mtx_t mtx) { // get internal cs im
     return &mtx->_Critical_section;
 }
 
-_CRTIMP2_PURE void __cdecl _Mtx_clear_owner(_Mtx_t mtx) { // set owner to nobody
-    mtx->_Thread_id = -1;
-    --mtx->_Count;
-}
-
-_CRTIMP2_PURE void __cdecl _Mtx_reset_owner(_Mtx_t mtx) { // set owner to current thread
-    mtx->_Thread_id = static_cast<long>(GetCurrentThreadId());
-    ++mtx->_Count;
-}
-
 _END_EXTERN_C
 
 /*
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
diff --git a/stl/src/xmtx.hpp b/stl/src/xmtx.hpp
index f36af7acfcd..2d5b7d1df5b 100644
--- a/stl/src/xmtx.hpp
+++ b/stl/src/xmtx.hpp
@@ -9,6 +9,15 @@
 
 #include <Windows.h>
 
+#ifdef _M_CEE
+#define _RELIABILITY_CONTRACT                                                    \
+    [System::Runtime::ConstrainedExecution::ReliabilityContract(                 \
+        System::Runtime::ConstrainedExecution::Consistency::WillNotCorruptState, \
+        System::Runtime::ConstrainedExecution::Cer::Success)]
+#else // ^^^ defined(_M_CEE) / !defined(_M_CEE) vvv
+#define _RELIABILITY_CONTRACT
+#endif // ^^^ !defined(_M_CEE) ^^^
+
 _EXTERN_C_UNLESS_PURE
 
 using _Rmtx = CRITICAL_SECTION;