diff --git a/contrib/cvs/src/tag.c b/contrib/cvs/src/tag.c
index ab4992f8696..903f3579078 100644
--- a/contrib/cvs/src/tag.c
+++ b/contrib/cvs/src/tag.c
@@ -10,6 +10,8 @@
  * Add or delete a symbolic name to an RCS file, or a collection of RCS files.
  * Tag uses the checked out revision in the current directory, rtag uses
  * the modules database, if necessary.
+ *
+ * $FreeBSD$
  */
 
 #include "cvs.h"
@@ -1199,6 +1201,9 @@ Numeric tag %s contains characters other than digits and '.'", name);
 	|| strcmp (name, TAG_HEAD) == 0)
 	return;
 
+    if (readonlyfs)
+	return;
+
     /* FIXME: This routine doesn't seem to do any locking whatsoever
        (and it is called from places which don't have locks in place).
        If two processes try to write val-tags at the same time, it would