diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index d99c1bbdabc..c37d3b1bfe3 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,21 @@
+2020-01-16  Kai-Uwe Eckhardt  <kuehro@gmx.de>
+	    Matthew Bauer  <mjbauer95@gmail.com>
+	    Jonathan Wakely  <jwakely@redhat.com>
+
+	PR bootstrap/64271 (partial)
+	* config/os/bsd/netbsd/ctype_base.h (ctype_base::mask): Change type
+	to unsigned short.
+	(ctype_base::alpha, ctype_base::digit, ctype_base::xdigit)
+	(ctype_base::print, ctype_base::graph, ctype_base::alnum): Sync
+	definitions with NetBSD upstream.
+	(ctype_base::blank): Use _CTYPE_BL.
+	* config/os/bsd/netbsd/ctype_configure_char.cc (_C_ctype_): Remove
+	Declaration.
+	(ctype<char>::classic_table): Use _C_ctype_tab_ instead of _C_ctype_.
+	(ctype<char>::do_toupper, ctype<char>::do_tolower): Cast char
+	parameters to unsigned char.
+	* config/os/bsd/netbsd/ctype_inline.h (ctype<char>::is): Likewise.
+
 2020-01-16  François Dumont  <fdumont@gcc.gnu.org>
 
 	PR libstdc++/91263
diff --git a/libstdc++-v3/config/os/bsd/netbsd/ctype_base.h b/libstdc++-v3/config/os/bsd/netbsd/ctype_base.h
index 340bd8e3d4e..28bf232ba83 100644
--- a/libstdc++-v3/config/os/bsd/netbsd/ctype_base.h
+++ b/libstdc++-v3/config/os/bsd/netbsd/ctype_base.h
@@ -43,35 +43,21 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
     // NB: Offsets into ctype<char>::_M_table force a particular size
     // on the mask type. Because of this, we don't use an enum.
-    typedef unsigned char      	mask;
+    typedef unsigned short      	mask;
 
-#ifndef _CTYPE_U
-    static const mask upper    	= _U;
-    static const mask lower 	= _L;
-    static const mask alpha 	= _U | _L;
-    static const mask digit 	= _N;
-    static const mask xdigit 	= _N | _X;
-    static const mask space 	= _S;
-    static const mask print 	= _P | _U | _L | _N | _B;
-    static const mask graph 	= _P | _U | _L | _N;
-    static const mask cntrl 	= _C;
-    static const mask punct 	= _P;
-    static const mask alnum 	= _U | _L | _N;
-#else
-    static const mask upper    	= _CTYPE_U;
-    static const mask lower 	= _CTYPE_L;
-    static const mask alpha 	= _CTYPE_U | _CTYPE_L;
-    static const mask digit 	= _CTYPE_N;
-    static const mask xdigit 	= _CTYPE_N | _CTYPE_X;
-    static const mask space 	= _CTYPE_S;
-    static const mask print 	= _CTYPE_P | _CTYPE_U | _CTYPE_L | _CTYPE_N | _CTYPE_B;
-    static const mask graph 	= _CTYPE_P | _CTYPE_U | _CTYPE_L | _CTYPE_N;
-    static const mask cntrl 	= _CTYPE_C;
-    static const mask punct 	= _CTYPE_P;
-    static const mask alnum 	= _CTYPE_U | _CTYPE_L | _CTYPE_N;
-#endif
+    static const mask upper	= _CTYPE_U;
+    static const mask lower	= _CTYPE_L;
+    static const mask alpha	= _CTYPE_A;
+    static const mask digit	= _CTYPE_D;
+    static const mask xdigit	= _CTYPE_X;
+    static const mask space	= _CTYPE_S;
+    static const mask print	= _CTYPE_R;
+    static const mask graph	= _CTYPE_G;
+    static const mask cntrl	= _CTYPE_C;
+    static const mask punct	= _CTYPE_P;
+    static const mask alnum	= _CTYPE_A | _CTYPE_D;
 #if __cplusplus >= 201103L
-    static const mask blank 	= space;
+    static const mask blank	= _CTYPE_BL;
 #endif
   };
 
diff --git a/libstdc++-v3/config/os/bsd/netbsd/ctype_configure_char.cc b/libstdc++-v3/config/os/bsd/netbsd/ctype_configure_char.cc
index 0680bb350c3..86f7828517d 100644
--- a/libstdc++-v3/config/os/bsd/netbsd/ctype_configure_char.cc
+++ b/libstdc++-v3/config/os/bsd/netbsd/ctype_configure_char.cc
@@ -38,11 +38,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 // Information as gleaned from /usr/include/ctype.h
 
-  extern "C" const u_int8_t _C_ctype_[];
-
   const ctype_base::mask*
   ctype<char>::classic_table() throw()
-  { return _C_ctype_ + 1; }
+  { return _C_ctype_tab_ + 1; }
 
   ctype<char>::ctype(__c_locale, const mask* __table, bool __del,
 		     size_t __refs)
@@ -69,14 +67,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   char
   ctype<char>::do_toupper(char __c) const
-  { return ::toupper((int) __c); }
+  { return ::toupper((int)(unsigned char) __c); }
 
   const char*
   ctype<char>::do_toupper(char* __low, const char* __high) const
   {
     while (__low < __high)
       {
-	*__low = ::toupper((int) *__low);
+	*__low = ::toupper((int)(unsigned char) *__low);
 	++__low;
       }
     return __high;
@@ -84,14 +82,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   char
   ctype<char>::do_tolower(char __c) const
-  { return ::tolower((int) __c); }
+  { return ::tolower((int)(unsigned char) __c); }
 
   const char*
   ctype<char>::do_tolower(char* __low, const char* __high) const
   {
     while (__low < __high)
       {
-	*__low = ::tolower((int) *__low);
+	*__low = ::tolower((int)(unsigned char) *__low);
 	++__low;
       }
     return __high;
diff --git a/libstdc++-v3/config/os/bsd/netbsd/ctype_inline.h b/libstdc++-v3/config/os/bsd/netbsd/ctype_inline.h
index 6395433e1ac..4536690b6d8 100644
--- a/libstdc++-v3/config/os/bsd/netbsd/ctype_inline.h
+++ b/libstdc++-v3/config/os/bsd/netbsd/ctype_inline.h
@@ -48,7 +48,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   is(const char* __low, const char* __high, mask* __vec) const
   {
     while (__low < __high)
-      *__vec++ = _M_table[*__low++];
+      *__vec++ = _M_table[(unsigned char)*__low++];
     return __high;
   }