diff --git a/lib/krb5/keytab.c b/lib/krb5/keytab.c
index d57a76922..92c3d8ae7 100644
--- a/lib/krb5/keytab.c
+++ b/lib/krb5/keytab.c
@@ -79,7 +79,37 @@ krb5_kt_add_entry(krb5_context context,
 		  krb5_keytab id,
 		  krb5_keytab_entry *entry)
 {
-  abort ();
+    int ret;
+    int fd;
+    krb5_storage *sp;
+
+    fd = open (id->filename, O_APPEND);
+    if (fd < 0) {
+	fd = open (id->filename, O_WRONLY | O_CREAT, 0600);
+	if (fd < 0)
+	    return -1;
+	sp = krb5_storage_from_fd(fd);
+	ret = krb5_store_int16 (sp, 0x0502);
+	if (ret) return ret;
+    } else {
+	sp = krb5_storage_from_fd(fd);
+    }
+
+    ret = krb5_store_int32 (sp, 4711); /* XXX */
+    if (ret) return ret;
+    ret = krb5_kt_store_principal (sp, entry->principal);
+    if (ret) return ret;
+    ret = krb5_store_int32 (sp, entry->principal->type);
+    if (ret) return ret;
+    ret = krb5_store_int32 (sp, time(NULL));
+    if (ret) return ret;
+    ret = krb5_store_int8 (sp, entry->vno);
+    if (ret) return ret;
+    ret = krb5_kt_store_keyblock (sp, &entry->keyblock);
+    if (ret) return ret;
+    krb5_storage_free (sp);
+    close (fd);
+    return 0;
 }
 
 krb5_error_code
@@ -197,6 +227,24 @@ krb5_kt_ret_data(krb5_storage *sp,
     return 0;
 }
 
+static krb5_error_code
+krb5_kt_store_principal(krb5_storage *sp,
+			krb5_principal princ)
+{
+    int i;
+    int ret;
+
+    ret = krb5_store_int16 (sp, princ->ncomp);
+    if (ret) return ret;
+    ret = krb5_kt_store_data (sp, princ->realm);
+    if (ret) return ret;
+    for (i = 0; i < princ->ncomp; i++) {
+	ret = krb5_kt_store_data (sp, princ->comp[i]);
+	if (ret) return ret;
+    }
+    return 0;
+}
+
 static krb5_error_code
 krb5_kt_ret_principal(krb5_storage *sp,
 		      krb5_principal *princ)
@@ -242,6 +290,19 @@ krb5_kt_ret_keyblock(krb5_storage *sp, krb5_keyblock *p)
     return ret;
 }
 
+static krb5_error_code
+krb5_kt_store_keyblock (krb5_storage *sp,
+			krb5_keyblock *p)
+{
+    int ret;
+
+    ret = krb5_store_int16(sp, p->keytype);
+    if (ret) return ret;
+    ret = krb5_kt_store_data(sp, p->contents);
+    if (ret) return ret;
+    return 0;
+}
+
 krb5_error_code
 krb5_kt_next_entry(krb5_context context,
 		   krb5_keytab id,