diff --git a/ncurses/wcwidth.h b/ncurses/wcwidth.h
index e261170..76673da 100644
--- a/ncurses/wcwidth.h
+++ b/ncurses/wcwidth.h
@@ -59,6 +59,16 @@
  * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
  */
 
+#ifndef _WCWIDTH_H_incl
+#define _WCWIDTH_H_incl 1
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <ncurses_cfg.h>
+#include <ncurses_dll.h>
+
 #include <wchar.h>
 
 struct interval {
@@ -119,7 +129,7 @@
  * in ISO 10646.
  */
 
-int mk_wcwidth(wchar_t ucs)
+NCURSES_EXPORT(int) mk_wcwidth(wchar_t ucs)
 {
   /* sorted list of non-overlapping intervals of non-spacing characters */
   /* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */
@@ -187,7 +197,7 @@
 
   /* if we arrive here, ucs is not a combining or C0/C1 control character */
 
-  return 1 + 
+  return 1 +
     (ucs >= 0x1100 &&
      (ucs <= 0x115f ||                    /* Hangul Jamo init. consonants */
       ucs == 0x2329 || ucs == 0x232a ||
@@ -207,7 +217,7 @@
 }
 
 
-int mk_wcswidth(const wchar_t *pwcs, size_t n)
+NCURSES_EXPORT(int) mk_wcswidth(const wchar_t *pwcs, size_t n)
 {
   int w, width = 0;
 
@@ -230,7 +240,7 @@
  * the traditional terminal character-width behaviour. It is not
  * otherwise recommended for general use.
  */
-int mk_wcwidth_cjk(wchar_t ucs)
+NCURSES_EXPORT(int) mk_wcwidth_cjk(wchar_t ucs)
 {
   /* sorted list of non-overlapping intervals of East Asian Ambiguous
    * characters, generated by "uniset +WIDTH-A -cat=Me -cat=Mn -cat=Cf c" */
@@ -298,7 +308,7 @@
 }
 
 
-int mk_wcswidth_cjk(const wchar_t *pwcs, size_t n)
+NCURSES_EXPORT(int) mk_wcswidth_cjk(const wchar_t *pwcs, size_t n)
 {
   int w, width = 0;
 
@@ -310,3 +320,9 @@
 
   return width;
 }
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _WCWIDTH_H_incl 1 */