diff --git a/src/common/regex.cpp b/src/common/regex.cpp
index 7d0efb3acc..44160b0ff7 100644
--- a/src/common/regex.cpp
+++ b/src/common/regex.cpp
@@ -52,12 +52,6 @@
 
 #include "wx/regex.h"
 
-#if wxUSE_UNICODE
-#   if !defined(wxUSE_BUILTIN_REGEX)
-#       error "Unicode not supported with system regex, please reconfigure with --with-regex=builtin"
-#   endif
-#endif
-
 // ----------------------------------------------------------------------------
 // private classes
 // ----------------------------------------------------------------------------
diff --git a/src/regex/regex.h b/src/regex/regex.h
index 6b7539ba8b..304e15d95e 100644
--- a/src/regex/regex.h
+++ b/src/regex/regex.h
@@ -44,7 +44,6 @@ extern "C" {
     WXWINDOWS CUSTOM 
 *****************************/
 #ifndef _REGEX_CUSTOM_H_
-#   define wxUSE_BUILTIN_REGEX
 #   define wx_wchar wxChar
 /*  FreeBSD, Watcom and DMars require this, CW doesn't have nor need it. */
 /*  Others also don't seem to need it. If you have an error related to */