diff --git a/include/wx/string.h b/include/wx/string.h
index b5b8104dea..c3380f25ec 100644
--- a/include/wx/string.h
+++ b/include/wx/string.h
@@ -346,7 +346,7 @@ public:
 
 #if wxUSE_WCHAR_T
     // from wide (Unicode) string
-  wxString(const wchar_t *pwz, wxMBConv& conv = wxConvLibc);
+  wxString(const wchar_t *pwz, wxMBConv& conv = wxConvLibc, size_t nLength = wxSTRING_MAXLEN);
 #endif // !wxUSE_WCHAR_T
 
     // from wxCharBuffer
diff --git a/src/common/string.cpp b/src/common/string.cpp
index d0297f3c97..134cd452c6 100644
--- a/src/common/string.cpp
+++ b/src/common/string.cpp
@@ -340,10 +340,17 @@ wxString::wxString(const char *psz, wxMBConv& conv, size_t nLength)
 
 #if wxUSE_WCHAR_T
 // from wide string
-wxString::wxString(const wchar_t *pwz, wxMBConv& conv)
+wxString::wxString(const wchar_t *pwz, wxMBConv& conv, size_t nLength)
 {
   // first get necessary size
-  size_t nLen = pwz ? conv.WC2MB((char *) NULL, pwz, 0) : 0;
+  size_t nLen = 0;
+  if (pwz)
+  {
+    if (nLength == wxSTRING_MAXLEN)
+      nLen = conv.WC2MB((char *) NULL, pwz, 0);
+    else
+      nLen = nLength;
+  }
 
   // empty?
   if ( (nLen != 0) && (nLen != (size_t)-1) ) {