diff --git a/src/chars.c b/src/chars.c
index 6da82e926219b706e129256ed5e7a62e0f1223c1..8080b77578a954a9a7aafb4c63ea8d2ec0093562 100644
--- a/src/chars.c
+++ b/src/chars.c
@@ -301,7 +301,7 @@ char *make_mbchar(int chr, int *chr_mb_len)
     return chr_mb;
 }
 
-#ifdef ENABLE_NANORC
+#if defined(ENABLE_NANORC) || defined(ENABLE_EXTRA)
 /* Convert the string str to a valid multibyte string with the same wide
  * character values as str.  Return the (dynamically allocated)
  * multibyte string. */
diff --git a/src/proto.h b/src/proto.h
index f5780014a2d57a35bbaea97575d97d372087793f..a976c22a2217830ff6d7fb71c6bbbc48da132b9e 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -175,7 +175,7 @@ wchar_t control_wrep(wchar_t c);
 int mbwidth(const char *c);
 int mb_cur_max(void);
 char *make_mbchar(int chr, int *chr_mb_len);
-#ifdef ENABLE_NANORC
+#if defined(ENABLE_NANORC) || defined(ENABLE_EXTRA)
 char *make_mbstring(const char *str);
 #endif
 int parse_mbchar(const char *buf, char *chr, bool *bad_chr, size_t
diff --git a/src/winio.c b/src/winio.c
index 6a667df91d2cabca1c3f837791fac7963fdcc678..440b6c556190543b0b8e6221e62a72de307e16c4 100644
--- a/src/winio.c
+++ b/src/winio.c
@@ -4123,6 +4123,9 @@ void do_credits(void)
 	    char *what;
 	    size_t start_x;
 
+	    /* Make sure every credit is a valid multibyte string, since
+	     * we can't dynamically set the credits to their multibyte
+	     * equivalents when we need to.  Sigh... */
 	    if (credits[crpos] == NULL) {
 		assert(0 <= xlpos && xlpos < XLCREDIT_LEN);