diff --git a/src/ui.c b/src/ui.c
index c835305..49bc56b 100644
--- a/src/ui.c
+++ b/src/ui.c
@@ -1458,7 +1458,7 @@
 
     int
 clip_gen_owner_exists(cbd)
-    VimClipboard	*cbd;
+    VimClipboard	*cbd UNUSED;
 {
 #ifdef FEAT_XCLIPBOARD
 # ifdef FEAT_GUI_GTK
@@ -2134,7 +2134,7 @@
 	text_prop.encoding = *type;
 	text_prop.format = *format;
 	text_prop.nitems = len;
-#ifdef FEAT_MBYTE
+#if defined(FEAT_MBYTE) && defined(X_HAVE_UTF8_STRING)
 	if (*type == utf8_atom)
 	    status = Xutf8TextPropertyToTextList(X_DISPLAY, &text_prop,
 							 &text_list, &n_text);
@@ -2196,8 +2196,13 @@
 	    default: type = XA_STRING;
 	}
 #ifdef FEAT_MBYTE
-	if (type == utf8_atom && !enc_utf8)
-	    /* Only request utf-8 when 'encoding' is utf8. */
+	if (type == utf8_atom
+# if defined(X_HAVE_UTF8_STRING)
+		&& !enc_utf8
+# endif
+		)
+	    /* Only request utf-8 when 'encoding' is utf8 and
+	     * Xutf8TextPropertyToTextList is available. */
 	    continue;
 #endif
 	success = MAYBE;