diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 10e3186..1e52a48 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -19190,6 +19190,38 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
     in the database's default tablespace, the tablespace can be specified as 0.
    </para>
 
+   <para>
+   Operating system collations are loaded with the
+   <function>pg_import_system_collations</> function, shown in <xref
+   linkend="functions-import-collation">.
+   </para>
+
+   <table id="functions-import-collation">
+    <title>Collation Functions</title>
+    <tgroup cols="3">
+     <thead>
+      <row><entry>Name</entry> <entry>Return Type</entry> <entry>Description</entry></row>
+     </thead>
+
+     <tbody>
+      <row>
+       <entry>
+        <indexterm><primary>pg_import_system_collations</primary></indexterm>
+        <literal><function>pg_import_system_collations(<parameter>schema</> <type>regnamespace</>, <parameter>if_not_exists</> <type>boolean</>)</function></literal>
+       </entry>
+       <entry><type>void</type></entry>
+       <entry>Import operating system collations</entry>
+      </row>
+     </tbody>
+    </tgroup>
+   </table>
+
+   <para>
+   <function>pg_import_system_collations</> loads collations that it finds on
+   the operating system into system catalog <literal>pg_collation</literal>,
+   skipping those that are already present.
+   </para>
+
   </sect2>
 
   <sect2 id="functions-admin-index">
diff --git a/src/backend/catalog/pg_collation.c b/src/backend/catalog/pg_collation.c
index 63c2eb9..694c0f6 100644
--- a/src/backend/catalog/pg_collation.c
+++ b/src/backend/catalog/pg_collation.c
@@ -98,10 +98,21 @@ CollationCreate(const char *collname, Oid collnamespace,
 							  PointerGetDatum(collname),
 							  Int32GetDatum(-1),
 							  ObjectIdGetDatum(collnamespace)))
-		ereport(ERROR,
+	{
+		if (if_not_exists)
+		{
+			ereport(NOTICE,
+				(errcode(ERRCODE_DUPLICATE_OBJECT),
+				 errmsg("collation \"%s\" already exists, skipping",
+						collname)));
+			return InvalidOid;
+		}
+		else
+			ereport(ERROR,
 				(errcode(ERRCODE_DUPLICATE_OBJECT),
 				 errmsg("collation \"%s\" already exists",
 						collname)));
+	}
 
 	/* open pg_collation */
 	rel = heap_open(CollationRelationId, RowExclusiveLock);
diff --git a/src/backend/commands/collationcmds.c b/src/backend/commands/collationcmds.c
index e108b50..cf3acea 100644
--- a/src/backend/commands/collationcmds.c
+++ b/src/backend/commands/collationcmds.c
@@ -139,7 +139,7 @@ DefineCollation(ParseState *pstate, List *names, List *parameters)
 							 collctype,
 							 false);
 
-	if (!newoid)
+	if (!OidIsValid(newoid))
 		return InvalidObjectAddress;
 
 	ObjectAddressSet(address, CollationRelationId, newoid);
@@ -183,6 +183,7 @@ IsThereCollationInNamespace(const char *collname, Oid nspOid)
 }
 
 
+#ifdef HAVE_LOCALE_T
 /*
  * "Normalize" a locale name, stripping off encoding tags such as
  * ".utf8" (e.g., "en_US.utf8" -> "en_US", but "br_FR.iso885915@euro"
@@ -216,13 +217,15 @@ normalize_locale_name(char *new, const char *old)
 
 	return changed;
 }
+#endif	/* HAVE_LOCALE_T */
 
 
 Datum
 pg_import_system_collations(PG_FUNCTION_ARGS)
 {
-	bool		if_not_exists = PG_GETARG_BOOL(0);
-	Oid         nspid = PG_GETARG_OID(1);
+#if defined(HAVE_LOCALE_T) && !defined(WIN32)
+	Oid         nspid = PG_GETARG_OID(0);
+	bool		if_not_exists = PG_GETARG_BOOL(1);
 
 	FILE	   *locale_a_handle;
 	char		localebuf[NAMEDATALEN]; /* we assume ASCII so this is fine */
@@ -321,6 +324,7 @@ pg_import_system_collations(PG_FUNCTION_ARGS)
 	if (count == 0)
 		ereport(ERROR,
 				(errmsg("no usable system locales were found")));
+#endif	/* not HAVE_LOCALE_T && not WIN32 */
 
 	PG_RETURN_VOID();
 }
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index b0126a9..bb8637e 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -5345,7 +5345,7 @@ DESCR("pg_controldata recovery state information as a function");
 DATA(insert OID = 3444 ( pg_control_init PGNSP PGUID 12 1 0 0 0 f f f f t f v s 0 0 2249 "" "{23,23,23,23,23,23,23,23,23,16,16,16,23}" "{o,o,o,o,o,o,o,o,o,o,o,o,o}" "{max_data_alignment,database_block_size,blocks_per_segment,wal_block_size,bytes_per_wal_segment,max_identifier_length,max_index_columns,max_toast_chunk_size,large_object_chunk_size,bigint_timestamps,float4_pass_by_value,float8_pass_by_value,data_page_checksum_version}" _null_ _null_ pg_control_init _null_ _null_ _null_ ));
 DESCR("pg_controldata init state information as a function");
 
-DATA(insert OID = 3445 ( pg_import_system_collations PGNSP PGUID 12 100 0 0 0 f f f f t f v r 2 0 2278 "16 4089" _null_ _null_ "{if_not_exists,schema}" _null_ _null_ pg_import_system_collations _null_ _null_ _null_ ));
+DATA(insert OID = 3445 ( pg_import_system_collations PGNSP PGUID 12 100 0 0 0 f f f f t f v r 2 0 2278 "4089 16" _null_ _null_ "{schema,if_not_exists}" _null_ _null_ pg_import_system_collations _null_ _null_ _null_ ));
 DESCR("import collations from operating system");
 
 /*