diff --git a/ui/curses.c b/ui/curses.c
index 1f3fcabb00..e9319eb8ae 100644
--- a/ui/curses.c
+++ b/ui/curses.c
@@ -489,9 +489,9 @@ static uint16_t get_ucs(wchar_t wch, iconv_t conv)
     memset(&ps, 0, sizeof(ps));
     ret = wcrtomb(mbch, wch, &ps);
     if (ret == -1) {
-        fprintf(stderr, "Could not convert 0x%04x "
+        fprintf(stderr, "Could not convert 0x%04lx "
                         "from wchar_t to a multibyte character: %s\n",
-                        wch, strerror(errno));
+                        (unsigned long)wch, strerror(errno));
         return 0xFFFD;
     }
 
@@ -501,9 +501,9 @@ static uint16_t get_ucs(wchar_t wch, iconv_t conv)
     such = sizeof(uch);
 
     if (iconv(conv, &pmbch, &smbch, &puch, &such) == (size_t) -1) {
-        fprintf(stderr, "Could not convert 0x%04x "
+        fprintf(stderr, "Could not convert 0x%04lx "
                         "from a multibyte character to UCS-2 : %s\n",
-                        wch, strerror(errno));
+                        (unsigned long)wch, strerror(errno));
         return 0xFFFD;
     }