diff --git a/src/chars.c b/src/chars.c
index 9e39bf9f4fc9accc998d3070d554f938efdaa8f8..456d18be823feed1f5f6fedbe93f63d5cdb6f9dc 100644
--- a/src/chars.c
+++ b/src/chars.c
@@ -79,7 +79,6 @@ bool is_alnum_wchar(wchar_t wc)
 {
     return iswalnum(wc);
 }
-#endif
 
 /* This function is equivalent to isascii(). */
 bool is_ascii_char(int c)
@@ -92,6 +91,7 @@ bool is_ascii_char(int c)
 #endif
 	;
 }
+#endif
 
 /* This function is equivalent to isblank(). */
 bool is_blank_char(int c)
diff --git a/src/nano.c b/src/nano.c
index 220c35b14bfb6fdfb9556d08a564a95a3e192421..6cdf7bfe6480a7870670223af95797680a7d4f9b 100644
--- a/src/nano.c
+++ b/src/nano.c
@@ -3616,11 +3616,15 @@ int do_input(bool *meta_key, bool *func_key, bool *s_or_t, bool
 
     if (allow_funcs) {
 	/* If we got a character, and it isn't a shortcut, toggle, or
-	 * ASCII control character, it's a normal text character.
-	 * Display the warning if we're in view mode, or add the
-	 * character to the input buffer if we're not. */
-	if (input != ERR && *s_or_t == FALSE &&
-		(!is_ascii_char(input) || !is_cntrl_char(input))) {
+	 * control character, it's a normal text character.  Display the
+	 * warning if we're in view mode, or add the character to the
+	 * input buffer if we're not. */
+	if (input != ERR && *s_or_t == FALSE && (
+#ifdef NANO_WIDE
+		/* Keep non-ASCII control characters in UTF-8 mode. */
+		(!ISSET(NO_UTF8) && !is_ascii_char(input)) ||
+#endif
+		!is_cntrl_char(input))) {
 	    if (ISSET(VIEW_MODE))
 		print_view_warning();
 	    else {
diff --git a/src/winio.c b/src/winio.c
index 78ba2f7af7c22831b69482abac4eb8a73a7e7f37..eb656a747dd45def76741d2cf5421f7f1657b1d0 100644
--- a/src/winio.c
+++ b/src/winio.c
@@ -1677,11 +1677,15 @@ int do_statusbar_input(bool *meta_key, bool *func_key, bool *s_or_t,
 
     if (allow_funcs) {
 	/* If we got a character, and it isn't a shortcut, toggle, or
-	 * ASCII control character, it's a normal text character.
-	 * Display the warning if we're in view mode, or add the
-	 * character to the input buffer if we're not. */
-	if (input != ERR && *s_or_t == FALSE &&
-		(!is_ascii_char(input) || !is_cntrl_char(input))) {
+	 * control character, it's a normal text character.  Display the
+	 * warning if we're in view mode, or add the character to the
+	 * input buffer if we're not. */
+	if (input != ERR && *s_or_t == FALSE && (
+#ifdef NANO_WIDE
+		/* Keep non-ASCII control characters in UTF-8 mode. */
+		(!ISSET(NO_UTF8) && !is_ascii_char(input)) ||
+#endif
+		!is_cntrl_char(input))) {
 	    /* If we're using restricted mode, the filename isn't blank,
 	     * and we're at the "Write File" prompt, disable text
 	     * input. */