diff --git a/contrib/pg_upgrade/option.c b/contrib/pg_upgrade/option.c
index bb594dd2f69..cfc88ec03be 100644
--- a/contrib/pg_upgrade/option.c
+++ b/contrib/pg_upgrade/option.c
@@ -137,17 +137,35 @@ parseCommandLine(int argc, char *argv[])
 				break;
 
 			case 'o':
-				old_cluster.pgopts = pg_strdup(optarg);
+				/* append option? */
+				if (!old_cluster.pgopts)
+					old_cluster.pgopts = pg_strdup(optarg);
+				else
+				{
+					char *old_pgopts = old_cluster.pgopts;
+
+					old_cluster.pgopts = psprintf("%s %s", old_pgopts, optarg);
+					free(old_pgopts);
+				}
 				break;
 
 			case 'O':
-				new_cluster.pgopts = pg_strdup(optarg);
+				/* append option? */
+				if (!new_cluster.pgopts)
+					new_cluster.pgopts = pg_strdup(optarg);
+				else
+				{
+					char *new_pgopts = new_cluster.pgopts;
+
+					new_cluster.pgopts = psprintf("%s %s", new_pgopts, optarg);
+					free(new_pgopts);
+				}
 				break;
 
 				/*
 				 * Someday, the port number option could be removed and passed
 				 * using -o/-O, but that requires postmaster -C to be
-				 * supported on all old/new versions.
+				 * supported on all old/new versions (added in PG 9.2).
 				 */
 			case 'p':
 				if ((old_cluster.port = atoi(optarg)) <= 0)
diff --git a/doc/src/sgml/pgupgrade.sgml b/doc/src/sgml/pgupgrade.sgml
index b79f0db7de4..dd57c5ca5ad 100644
--- a/doc/src/sgml/pgupgrade.sgml
+++ b/doc/src/sgml/pgupgrade.sgml
@@ -130,14 +130,16 @@
       <term><option>-o</option> <replaceable class="parameter">options</replaceable></term>
       <term><option>--old-options</option> <replaceable class="parameter">options</replaceable></term>
       <listitem><para>options to be passed directly to the
-      old <command>postgres</command> command</para></listitem>
+      old <command>postgres</command> command;  multiple
+      option invocations are appended</para></listitem>
      </varlistentry>
 
      <varlistentry>
       <term><option>-O</option> <replaceable class="parameter">options</replaceable></term>
       <term><option>--new-options</option> <replaceable class="parameter">options</replaceable></term>
       <listitem><para>options to be passed directly to the
-      new <command>postgres</command> command</para></listitem>
+      new <command>postgres</command> command;  multiple
+      option invocations are appended</para></listitem>
      </varlistentry>
 
      <varlistentry>
diff --git a/doc/src/sgml/ref/pg_ctl-ref.sgml b/doc/src/sgml/ref/pg_ctl-ref.sgml
index 23681294b87..29f882bd76e 100644
--- a/doc/src/sgml/ref/pg_ctl-ref.sgml
+++ b/doc/src/sgml/ref/pg_ctl-ref.sgml
@@ -302,7 +302,8 @@ PostgreSQL documentation
       <listitem>
        <para>
         Specifies options to be passed directly to the
-        <command>postgres</command> command.
+        <command>postgres</command> command;  multiple
+        option invocations are appended.
        </para>
        <para>
         The options should usually be surrounded by single or double
diff --git a/doc/src/sgml/ref/postgres-ref.sgml b/doc/src/sgml/ref/postgres-ref.sgml
index cdfdaa0b397..845d96940b0 100644
--- a/doc/src/sgml/ref/postgres-ref.sgml
+++ b/doc/src/sgml/ref/postgres-ref.sgml
@@ -288,7 +288,8 @@ PostgreSQL documentation
         class="parameter">extra-options</replaceable> are passed to
         all server processes started by this
         <command>postgres</command> process.  If the option string contains
-        any spaces, the entire string must be quoted.
+        any spaces, the entire string must be quoted;  multiple
+        option invocations are appended.
        </para>
 
        <para>
diff --git a/src/bin/pg_ctl/pg_ctl.c b/src/bin/pg_ctl/pg_ctl.c
index ad7f36cdd2b..a46ca53ba6e 100644
--- a/src/bin/pg_ctl/pg_ctl.c
+++ b/src/bin/pg_ctl/pg_ctl.c
@@ -2184,7 +2184,16 @@ main(int argc, char **argv)
 					register_servicename = pg_strdup(optarg);
 					break;
 				case 'o':
-					post_opts = pg_strdup(optarg);
+					/* append option? */
+					if (!post_opts)
+						post_opts = pg_strdup(optarg);
+					else
+					{
+						char *old_post_opts = post_opts;
+
+						post_opts = psprintf("%s %s", old_post_opts, optarg);
+						free(old_post_opts);
+					}
 					break;
 				case 'p':
 					exec_path = pg_strdup(optarg);