diff --git a/build/cmake/init.cmake b/build/cmake/init.cmake
index 576f8506e2..ab17223baf 100644
--- a/build/cmake/init.cmake
+++ b/build/cmake/init.cmake
@@ -194,9 +194,6 @@ endif()
 
 # Constants for setup.h creation
 set(wxUSE_STD_DEFAULT ON)
-if(wxUSE_UNICODE)
-    set(wxUSE_WCHAR_T ON)
-endif()
 if(NOT wxUSE_EXPAT)
     set(wxUSE_XRC OFF)
 endif()
diff --git a/build/cmake/setup.h.in b/build/cmake/setup.h.in
index 2ee13d6522..d8dae8ada1 100644
--- a/build/cmake/setup.h.in
+++ b/build/cmake/setup.h.in
@@ -182,8 +182,6 @@
     #cmakedefine01 wxUSE_UNICODE
 #endif
 
-#cmakedefine01 wxUSE_WCHAR_T
-
 
 #cmakedefine01 wxUSE_EXCEPTIONS
 
diff --git a/configure b/configure
index 83cc27e66a..195d09867a 100755
--- a/configure
+++ b/configure
@@ -19573,8 +19573,6 @@ _ACEOF
 if test "$ac_cv_sizeof_wchar_t" = 0; then
     as_fn_error $? "wxWidgets requires wchar_t support." "$LINENO" 5
 fi
-$as_echo "#define wxUSE_WCHAR_T 1" >>confdefs.h
-
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for va_copy" >&5
 $as_echo_n "checking for va_copy... " >&6; }
diff --git a/configure.in b/configure.in
index 97e351c8f9..41f15e386b 100644
--- a/configure.in
+++ b/configure.in
@@ -1561,7 +1561,6 @@ AC_CHECK_SIZEOF(wchar_t, 0,
 if test "$ac_cv_sizeof_wchar_t" = 0; then
     AC_MSG_ERROR([wxWidgets requires wchar_t support.])
 fi
-AC_DEFINE(wxUSE_WCHAR_T)
 
 dnl checks needed to define wxVaCopy
 AC_CACHE_CHECK([for va_copy],
diff --git a/include/wx/android/setup.h b/include/wx/android/setup.h
index 0055c63e43..a1a344adae 100644
--- a/include/wx/android/setup.h
+++ b/include/wx/android/setup.h
@@ -183,7 +183,7 @@
 // Unicode support
 // ----------------------------------------------------------------------------
 
-// These settings are obsolete: the library is always built in Unicode mode
+// This option is deprecated: the library should be always built in Unicode mode
 // now, only set wxUSE_UNICODE to 0 to compile legacy code in ANSI mode if
 // absolutely necessary -- updating it is strongly recommended as the ANSI mode
 // will disappear completely in future wxWidgets releases.
@@ -191,9 +191,6 @@
     #define wxUSE_UNICODE 1
 #endif
 
-// wxUSE_WCHAR_T is required by wxWidgets now, don't change.
-#define wxUSE_WCHAR_T 1
-
 // ----------------------------------------------------------------------------
 // global features
 // ----------------------------------------------------------------------------
diff --git a/include/wx/chartype.h b/include/wx/chartype.h
index 9a3a805a21..b29c1a6a0c 100644
--- a/include/wx/chartype.h
+++ b/include/wx/chartype.h
@@ -21,26 +21,9 @@
  */
 #include "wx/types.h"
 
-/* check whether we have wchar_t and which size it is if we do */
-#if !defined(wxUSE_WCHAR_T)
-    #if defined(__UNIX__)
-        #if defined(HAVE_WCSTR_H) || defined(HAVE_WCHAR_H) || defined(__FreeBSD__) || defined(__DARWIN__)
-            #define wxUSE_WCHAR_T 1
-        #else
-            #define wxUSE_WCHAR_T 0
-        #endif
-    #elif defined(__GNUWIN32__) && !defined(__MINGW32__)
-        #define wxUSE_WCHAR_T 0
-    #else
-        /* add additional compiler checks if this fails */
-        #define wxUSE_WCHAR_T 1
-    #endif
-#endif /* !defined(wxUSE_WCHAR_T) */
-
-/* Unicode support requires wchar_t */
-#if !wxUSE_WCHAR_T
-    #error "wchar_t must be available"
-#endif /* Unicode */
+/* This is kept only for backwards compatibility, in case some application code
+   checks for it. It's always 1 and can't be changed. */
+#define wxUSE_WCHAR_T 1
 
 /*
    non Unix compilers which do have wchar.h (but not tchar.h which is included
@@ -123,11 +106,6 @@
 #ifdef wxHAVE_TCHAR_SUPPORT
     /* get TCHAR definition if we've got it */
     #include <tchar.h>
-
-    /* we surely do have wchar_t if we have TCHAR */
-    #ifndef wxUSE_WCHAR_T
-        #define wxUSE_WCHAR_T 1
-    #endif /* !defined(wxUSE_WCHAR_T) */
 #endif /* wxHAVE_TCHAR_SUPPORT */
 
 /* ------------------------------------------------------------------------- */
diff --git a/include/wx/gtk/setup0.h b/include/wx/gtk/setup0.h
index 715cea602a..5045f30ea8 100644
--- a/include/wx/gtk/setup0.h
+++ b/include/wx/gtk/setup0.h
@@ -184,7 +184,7 @@
 // Unicode support
 // ----------------------------------------------------------------------------
 
-// These settings are obsolete: the library is always built in Unicode mode
+// This option is deprecated: the library should be always built in Unicode mode
 // now, only set wxUSE_UNICODE to 0 to compile legacy code in ANSI mode if
 // absolutely necessary -- updating it is strongly recommended as the ANSI mode
 // will disappear completely in future wxWidgets releases.
@@ -192,9 +192,6 @@
     #define wxUSE_UNICODE 1
 #endif
 
-// wxUSE_WCHAR_T is required by wxWidgets now, don't change.
-#define wxUSE_WCHAR_T 1
-
 // ----------------------------------------------------------------------------
 // global features
 // ----------------------------------------------------------------------------
diff --git a/include/wx/motif/setup0.h b/include/wx/motif/setup0.h
index 5a5e8137ad..5644bfd481 100644
--- a/include/wx/motif/setup0.h
+++ b/include/wx/motif/setup0.h
@@ -184,7 +184,7 @@
 // Unicode support
 // ----------------------------------------------------------------------------
 
-// These settings are obsolete: the library is always built in Unicode mode
+// This option is deprecated: the library should be always built in Unicode mode
 // now, only set wxUSE_UNICODE to 0 to compile legacy code in ANSI mode if
 // absolutely necessary -- updating it is strongly recommended as the ANSI mode
 // will disappear completely in future wxWidgets releases.
@@ -192,9 +192,6 @@
     #define wxUSE_UNICODE 1
 #endif
 
-// wxUSE_WCHAR_T is required by wxWidgets now, don't change.
-#define wxUSE_WCHAR_T 1
-
 // ----------------------------------------------------------------------------
 // global features
 // ----------------------------------------------------------------------------
diff --git a/include/wx/msw/chkconf.h b/include/wx/msw/chkconf.h
index baf02f7e4e..3ca6761472 100644
--- a/include/wx/msw/chkconf.h
+++ b/include/wx/msw/chkconf.h
@@ -175,14 +175,6 @@
 #   undef  wxUSE_DEBUG_NEW_ALWAYS
 #   define wxUSE_DEBUG_NEW_ALWAYS          0
 
-/* some Cygwin versions don't have wcslen */
-#   if defined(__CYGWIN__) || defined(__CYGWIN32__)
-#   if ! ((__GNUC__>2) ||((__GNUC__==2) && (__GNUC_MINOR__>=95)))
-#       undef wxUSE_WCHAR_T
-#       define wxUSE_WCHAR_T 0
-#   endif
-#endif
-
 #endif /* __GNUWIN32__ */
 
 /* MinGW32 doesn't provide wincred.h defining the API needed by this */
diff --git a/include/wx/msw/setup0.h b/include/wx/msw/setup0.h
index 1d1890f6cb..4f03064738 100644
--- a/include/wx/msw/setup0.h
+++ b/include/wx/msw/setup0.h
@@ -184,7 +184,7 @@
 // Unicode support
 // ----------------------------------------------------------------------------
 
-// These settings are obsolete: the library is always built in Unicode mode
+// This option is deprecated: the library should be always built in Unicode mode
 // now, only set wxUSE_UNICODE to 0 to compile legacy code in ANSI mode if
 // absolutely necessary -- updating it is strongly recommended as the ANSI mode
 // will disappear completely in future wxWidgets releases.
@@ -192,9 +192,6 @@
     #define wxUSE_UNICODE 1
 #endif
 
-// wxUSE_WCHAR_T is required by wxWidgets now, don't change.
-#define wxUSE_WCHAR_T 1
-
 // ----------------------------------------------------------------------------
 // global features
 // ----------------------------------------------------------------------------
diff --git a/include/wx/osx/setup0.h b/include/wx/osx/setup0.h
index a04f3fad08..8daa03e568 100644
--- a/include/wx/osx/setup0.h
+++ b/include/wx/osx/setup0.h
@@ -190,7 +190,7 @@
 // Unicode support
 // ----------------------------------------------------------------------------
 
-// These settings are obsolete: the library is always built in Unicode mode
+// This option is deprecated: the library should be always built in Unicode mode
 // now, only set wxUSE_UNICODE to 0 to compile legacy code in ANSI mode if
 // absolutely necessary -- updating it is strongly recommended as the ANSI mode
 // will disappear completely in future wxWidgets releases.
@@ -198,9 +198,6 @@
     #define wxUSE_UNICODE 1
 #endif
 
-// wxUSE_WCHAR_T is required by wxWidgets now, don't change.
-#define wxUSE_WCHAR_T 1
-
 // ----------------------------------------------------------------------------
 // global features
 // ----------------------------------------------------------------------------
diff --git a/include/wx/setup_inc.h b/include/wx/setup_inc.h
index 4706597287..6932a2c0db 100644
--- a/include/wx/setup_inc.h
+++ b/include/wx/setup_inc.h
@@ -180,7 +180,7 @@
 // Unicode support
 // ----------------------------------------------------------------------------
 
-// These settings are obsolete: the library is always built in Unicode mode
+// This option is deprecated: the library should be always built in Unicode mode
 // now, only set wxUSE_UNICODE to 0 to compile legacy code in ANSI mode if
 // absolutely necessary -- updating it is strongly recommended as the ANSI mode
 // will disappear completely in future wxWidgets releases.
@@ -188,9 +188,6 @@
     #define wxUSE_UNICODE 1
 #endif
 
-// wxUSE_WCHAR_T is required by wxWidgets now, don't change.
-#define wxUSE_WCHAR_T 1
-
 // ----------------------------------------------------------------------------
 // global features
 // ----------------------------------------------------------------------------
diff --git a/include/wx/univ/setup0.h b/include/wx/univ/setup0.h
index c48db8d762..7e7ff0e8a9 100644
--- a/include/wx/univ/setup0.h
+++ b/include/wx/univ/setup0.h
@@ -183,7 +183,7 @@
 // Unicode support
 // ----------------------------------------------------------------------------
 
-// These settings are obsolete: the library is always built in Unicode mode
+// This option is deprecated: the library should be always built in Unicode mode
 // now, only set wxUSE_UNICODE to 0 to compile legacy code in ANSI mode if
 // absolutely necessary -- updating it is strongly recommended as the ANSI mode
 // will disappear completely in future wxWidgets releases.
@@ -191,9 +191,6 @@
     #define wxUSE_UNICODE 1
 #endif
 
-// wxUSE_WCHAR_T is required by wxWidgets now, don't change.
-#define wxUSE_WCHAR_T 1
-
 // ----------------------------------------------------------------------------
 // global features
 // ----------------------------------------------------------------------------
diff --git a/setup.h.in b/setup.h.in
index fad308dc54..62fd583f36 100644
--- a/setup.h.in
+++ b/setup.h.in
@@ -182,8 +182,6 @@
     #define wxUSE_UNICODE 0
 #endif
 
-#define wxUSE_WCHAR_T 0
-
 
 #define wxUSE_EXCEPTIONS    0
 
diff --git a/setup.h_vms b/setup.h_vms
index 7b457b2a46..b3581318ef 100644
--- a/setup.h_vms
+++ b/setup.h_vms
@@ -218,8 +218,6 @@ typedef pid_t GPid;
 #endif
 #endif
 
-#define wxUSE_WCHAR_T 1
-
 
 #define wxUSE_EXCEPTIONS 1
 
diff --git a/src/html/helpdata.cpp b/src/html/helpdata.cpp
index 05af129704..6dcede915b 100644
--- a/src/html/helpdata.cpp
+++ b/src/html/helpdata.cpp
@@ -502,16 +502,12 @@ bool wxHtmlHelpData::AddBookParam(const wxFSFile& bookfile,
                                   const wxString& indexfile, const wxString& deftopic,
                                   const wxString& path)
 {
-#if wxUSE_WCHAR_T
-        #if wxUSE_UNICODE
-            #define CORRECT_STR(str, conv) \
-                str = wxString((str).mb_str(wxConvISO8859_1), conv)
-        #else
-            #define CORRECT_STR(str, conv) \
-                str = wxString((str).wc_str(conv), wxConvLocal)
-        #endif
+#if wxUSE_UNICODE
+    #define CORRECT_STR(str, conv) \
+        str = wxString((str).mb_str(wxConvISO8859_1), conv)
 #else
-    #define CORRECT_STR(str, conv)
+    #define CORRECT_STR(str, conv) \
+        str = wxString((str).wc_str(conv), wxConvLocal)
 #endif
 
     wxFileSystem fsys;