diff --git a/build/cmake/setup.cmake b/build/cmake/setup.cmake
index f97fc661d5..56b119dfcb 100644
--- a/build/cmake/setup.cmake
+++ b/build/cmake/setup.cmake
@@ -558,7 +558,6 @@ check_include_file(langinfo.h HAVE_LANGINFO_H)
 check_include_file(sched.h HAVE_SCHED_H)
 check_include_file(unistd.h HAVE_UNISTD_H)
 check_include_file(wchar.h HAVE_WCHAR_H)
-check_include_file(wcstr.h HAVE_WCSTR_H)
 
 if(wxUSE_DATETIME)
     # check for timezone variable:
diff --git a/build/cmake/setup.h.in b/build/cmake/setup.h.in
index ac4b4a488a..1205c86604 100644
--- a/build/cmake/setup.h.in
+++ b/build/cmake/setup.h.in
@@ -1049,9 +1049,6 @@
 /* Define if you have the <wchar.h> header file.  */
 #cmakedefine HAVE_WCHAR_H 1
 
-/* Define if you have the <wcstr.h> header file.  */
-#cmakedefine HAVE_WCSTR_H 1
-
 /* Define if you have <widec.h> (Solaris only) */
 #cmakedefine HAVE_WIDEC_H 1
 
diff --git a/configure b/configure
index 71a91b4a2b..75b2ff09b8 100755
--- a/configure
+++ b/configure
@@ -23676,22 +23676,6 @@ fi
 done
 
 
-if test "$ac_cv_header_wchar_h" != "yes"; then
-    for ac_header in wcstr.h
-do :
-  ac_fn_c_check_header_compile "$LINENO" "wcstr.h" "ac_cv_header_wcstr_h" "$ac_includes_default
-"
-if test "x$ac_cv_header_wcstr_h" = xyes; then :
-  cat >>confdefs.h <<_ACEOF
-#define HAVE_WCSTR_H 1
-_ACEOF
-
-fi
-
-done
-
-fi
-
 if test "$USE_UNIX" = 1 ; then
         for ac_header in sys/select.h
 do :
diff --git a/configure.ac b/configure.ac
index de5d941d03..7f02ef5210 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1573,11 +1573,6 @@ dnl Note: non-empty last parameter makes check compile-only,
 dnl   skipping worthless preprocessing check
 AC_CHECK_HEADERS(langinfo.h wchar.h,,, [AC_INCLUDES_DEFAULT])
 
-dnl maybe wchar_t is in wcstr.h if we don't have wchar.h?
-if test "$ac_cv_header_wchar_h" != "yes"; then
-    AC_CHECK_HEADERS([wcstr.h],,, [AC_INCLUDES_DEFAULT()])
-fi
-
 if test "$USE_UNIX" = 1 ; then
     dnl POSIX needs this for select(), but old systems don't have it
     AC_CHECK_HEADERS([sys/select.h],,, [AC_INCLUDES_DEFAULT()])
diff --git a/include/wx/chartype.h b/include/wx/chartype.h
index e2fdf1207f..f602bcb537 100644
--- a/include/wx/chartype.h
+++ b/include/wx/chartype.h
@@ -72,9 +72,6 @@
         #endif
     #endif /* Android */
 
-#elif defined(HAVE_WCSTR_H)
-    /* old compilers have relevant declarations here */
-    #include <wcstr.h>
 #elif defined(__FreeBSD__) || defined(__DARWIN__)
     /* include stdlib.h for wchar_t */
     #include <stdlib.h>
diff --git a/setup.h.in b/setup.h.in
index d69d3af885..cbe9811b95 100644
--- a/setup.h.in
+++ b/setup.h.in
@@ -1048,9 +1048,6 @@
 /* Define if you have the <wchar.h> header file.  */
 #undef HAVE_WCHAR_H
 
-/* Define if you have the <wcstr.h> header file.  */
-#undef HAVE_WCSTR_H
-
 /* Define if you have <widec.h> (Solaris only) */
 #undef HAVE_WIDEC_H
 
diff --git a/setup.h_vms b/setup.h_vms
index 4df6ff7cc3..e127271d98 100644
--- a/setup.h_vms
+++ b/setup.h_vms
@@ -1127,9 +1127,6 @@ typedef pid_t GPid;
 /* Define if you have the <wchar.h> header file.  */
 #define HAVE_WCHAR_H 1
 
-/* Define if you have the <wcstr.h> header file.  */
-#undef HAVE_WCSTR_H
-
 /* Define if you have the <wctype.h> header file.  */
 #if __CRTL_VER >= 70312000
 #define HAVE_WCTYPE_H 1