diff --git a/postfix/HISTORY b/postfix/HISTORY
index 815a6d9c4..c82088f23 100644
--- a/postfix/HISTORY
+++ b/postfix/HISTORY
@@ -13897,3 +13897,7 @@ Apologies for any names omitted.
 	Bugfix: the proxymap client didn't properly propagate the
 	postmap (postalias) -r and -w options to the proxymap server.
 	File: util/dict.h.
+
+	Workaround: force synchronous updates in the proxymap server
+	so that maps will be in a consistent state between updates.
+	File: proxymap/proxymap.c.
diff --git a/postfix/README_FILES/OVERVIEW b/postfix/README_FILES/OVERVIEW
index 8c95184de..cc6e83222 100644
--- a/postfix/README_FILES/OVERVIEW
+++ b/postfix/README_FILES/OVERVIEW
@@ -261,9 +261,10 @@ queues.
                                    ination
                                     logs
 
-  * The proxymap(8) servers provide read-only table lookup service to Postfix
-    processes. This overcomes chroot restrictions, and reduces the number of
-    open lookup tables by sharing one open table among multiple processes.
+  * The proxymap(8) servers provide read-only and read-write table lookup
+    service to Postfix processes. This overcomes chroot restrictions, reduces
+    the number of open lookup tables by sharing one open table among multiple
+    processes, and implements single-updater tables.
 
   * The scache(8) server maintains the connection cache for the Postfix smtp(8)
     client. When connection caching is enabled for selected destinations, the
diff --git a/postfix/html/OVERVIEW.html b/postfix/html/OVERVIEW.html
index 62f4afece..693f082cc 100644
--- a/postfix/html/OVERVIEW.html
+++ b/postfix/html/OVERVIEW.html
@@ -532,10 +532,12 @@ ination<br> logs </td> </tr>
 
 </table>
 
-<li> <p> The <a href="proxymap.8.html">proxymap(8)</a> servers provide read-only table lookup
+<li> <p> The <a href="proxymap.8.html">proxymap(8)</a> servers provide read-only and read-write
+table lookup
 service to Postfix processes. This overcomes chroot restrictions,
-and reduces the number of open lookup tables by sharing one open
-table among multiple processes. </p>
+reduces the number of open lookup tables by sharing one open
+table among multiple processes, and implements single-updater
+tables. </p>
 
 <li> <p> The <a href="scache.8.html">scache(8)</a> server maintains the connection cache for
 the Postfix <a href="smtp.8.html">smtp(8)</a> client. When connection caching is enabled for
diff --git a/postfix/html/proxymap.8.html b/postfix/html/proxymap.8.html
index 11c11055d..39a39c760 100644
--- a/postfix/html/proxymap.8.html
+++ b/postfix/html/proxymap.8.html
@@ -67,7 +67,7 @@ PROXYMAP(8)                                                        PROXYMAP(8)
 
               To implement single-updater maps, specify a process
               limit  of  1  in  the  <a href="master.5.html">master.cf</a> file entry for the
-              proxywrite service.
+              <b>proxywrite</b> service.
 
               This request is supported in Postfix 2.5 and later.
 
diff --git a/postfix/man/man8/proxymap.8 b/postfix/man/man8/proxymap.8
index 74a161c16..205e967c4 100644
--- a/postfix/man/man8/proxymap.8
+++ b/postfix/man/man8/proxymap.8
@@ -64,7 +64,8 @@ The \fImaptype:mapname\fR and \fIflags\fR are the same
 as with the \fBopen\fR request.
 .sp
 To implement single-updater maps, specify a process limit
-of 1 in the master.cf file entry for the proxywrite service.
+of 1 in the master.cf file entry for the \fBproxywrite\fR
+service.
 .sp
 This request is supported in Postfix 2.5 and later.
 .PP
diff --git a/postfix/proto/OVERVIEW.html b/postfix/proto/OVERVIEW.html
index 2a25fc398..924f38695 100644
--- a/postfix/proto/OVERVIEW.html
+++ b/postfix/proto/OVERVIEW.html
@@ -532,10 +532,12 @@ ination<br> logs </td> </tr>
 
 </table>
 
-<li> <p> The proxymap(8) servers provide read-only table lookup
+<li> <p> The proxymap(8) servers provide read-only and read-write
+table lookup
 service to Postfix processes. This overcomes chroot restrictions,
-and reduces the number of open lookup tables by sharing one open
-table among multiple processes. </p>
+reduces the number of open lookup tables by sharing one open
+table among multiple processes, and implements single-updater
+tables. </p>
 
 <li> <p> The scache(8) server maintains the connection cache for
 the Postfix smtp(8) client. When connection caching is enabled for
diff --git a/postfix/src/global/mail_version.h b/postfix/src/global/mail_version.h
index dd540c643..287cba84b 100644
--- a/postfix/src/global/mail_version.h
+++ b/postfix/src/global/mail_version.h
@@ -20,7 +20,7 @@
   * Patches change both the patchlevel and the release date. Snapshots have no
   * patchlevel; they change the release date only.
   */
-#define MAIL_RELEASE_DATE	"2007111203"
+#define MAIL_RELEASE_DATE	"2007111204"
 #define MAIL_VERSION_NUMBER	"2.5"
 
 #ifdef SNAPSHOT
diff --git a/postfix/src/proxymap/proxymap.c b/postfix/src/proxymap/proxymap.c
index a23a31031..c3b5e23d4 100644
--- a/postfix/src/proxymap/proxymap.c
+++ b/postfix/src/proxymap/proxymap.c
@@ -58,7 +58,8 @@
 /*	as with the \fBopen\fR request.
 /* .sp
 /*	To implement single-updater maps, specify a process limit
-/*	of 1 in the master.cf file entry for the proxywrite service.
+/*	of 1 in the master.cf file entry for the \fBproxywrite\fR
+/*	service.
 /* .sp
 /*	This request is supported in Postfix 2.5 and later.
 /* .PP
@@ -302,8 +303,6 @@ static DICT *proxy_map_find(const char *map_type_name, int request_flags,
 			 request_flags);
     if (dict == 0)
 	msg_panic("proxy_map_find: dict_open null result");
-    if (proxy_writer)
-	dict->flags |= DICT_FLAG_SYNC_UPDATE;
     dict_register(STR(map_type_name_flags), dict);
     return (dict);
 }
@@ -361,6 +360,12 @@ static void proxymap_update_service(VSTREAM *client_stream)
 
     /*
      * Process the request.
+     * 
+     * XXX We don't close maps, so we must turn on synchronous update to ensure
+     * that the on-disk data is in a consistent state between updates.
+     * 
+     * XXX We ignore duplicates, because the proxymap server would abort
+     * otherwise.
      */
     if (attr_scan(client_stream, ATTR_FLAG_STRICT,
 		  ATTR_TYPE_STR, MAIL_ATTR_TABLE, request_map,
@@ -378,7 +383,8 @@ static void proxymap_update_service(VSTREAM *client_stream)
 	 /* void */ ;
     } else {
 	dict->flags = ((dict->flags & ~DICT_FLAG_RQST_MASK)
-		       | (request_flags & DICT_FLAG_RQST_MASK));
+		       | (request_flags & DICT_FLAG_RQST_MASK)
+		       | DICT_FLAG_SYNC_UPDATE | DICT_FLAG_DUP_REPLACE);
 	dict_put(dict, STR(request_key), STR(request_value));
 	reply_status = PROXY_STAT_OK;
     }