diff --git a/xkb/xkbtext.c b/xkb/xkbtext.c
index 7f377fdfc..96d2a683e 100644
--- a/xkb/xkbtext.c
+++ b/xkb/xkbtext.c
@@ -174,14 +174,14 @@ XkbVModMaskText(XkbDescPtr xkb,
                 len = strlen(tmp) + 1 + (str == buf ? 0 : 1);
                 if (format == XkbCFile)
                     len += 4;
-                if ((str - (buf + len)) <= VMOD_BUFFER_SIZE) {
-                    if (str != buf) {
-                        if (format == XkbCFile)
-                            *str++ = '|';
-                        else
-                            *str++ = '+';
-                        len--;
-                    }
+                if ((str - buf) + len > VMOD_BUFFER_SIZE)
+                    continue; /* Skip */
+                if (str != buf) {
+                    if (format == XkbCFile)
+                        *str++ = '|';
+                    else
+                        *str++ = '+';
+                    len--;
                 }
                 if (format == XkbCFile)
                     sprintf(str, "%sMask", tmp);