diff --git a/doc/man/man5/slapd-sock.5 b/doc/man/man5/slapd-sock.5
index 1ac4f7fdd..903155fa4 100644
--- a/doc/man/man5/slapd-sock.5
+++ b/doc/man/man5/slapd-sock.5
@@ -49,7 +49,7 @@ be sent and from which replies are received.
 
 When used as an overlay, these additional directives are defined:
 .TP
-.B sockops	[ bind | unbind | search | compare | modify | modrdn | add | delete ]*
+.B sockops	[ bind | unbind | search | compare | modify | modrdn | add | delete | extended ]*
 Specify which request types to send to the external program. The default is
 empty (no requests are sent).
 .TP
@@ -115,6 +115,17 @@ dn: <DN>
 .PP
 .RS
 .nf
+EXTENDED
+msgid: <message id>
+<repeat { "suffix:" <database suffix DN> }>
+oid: <OID>
+value: <base64-value>
+<blank line>
+.fi
+.RE
+.PP
+.RS
+.nf
 MODIFY
 msgid: <message id>
 <repeat { "suffix:" <database suffix DN> }>
@@ -213,6 +224,11 @@ msgid: <message id>
 .fi
 .RE
 
+.SH KNOWN LIMITATIONS
+The 
+.B sock 
+backend does not process extended operation results from an external program.
+
 .SH ACCESS CONTROL
 The
 .B sock
@@ -292,6 +308,11 @@ access to the
 pseudo_attribute of the searchBase;
 .B search (=s)
 access to the attributes and values used in the filter is not checked.
+.LP
+The
+.B extended
+operation does not require any access special rights.
+The external program has to implement any sort of access control.
 
 .SH EXAMPLE
 There is an example script in the slapd/back\-sock/ directory
diff --git a/servers/slapd/back-sock/Makefile.in b/servers/slapd/back-sock/Makefile.in
index 3e527e545..efb916246 100644
--- a/servers/slapd/back-sock/Makefile.in
+++ b/servers/slapd/back-sock/Makefile.in
@@ -18,9 +18,9 @@
 ## in OpenLDAP Software.
 
 SRCS	= init.c config.c opensock.c search.c bind.c unbind.c add.c \
-		delete.c modify.c modrdn.c compare.c result.c
+		delete.c modify.c modrdn.c compare.c result.c extended.c
 OBJS	= init.lo config.lo opensock.lo search.lo bind.lo unbind.lo add.lo \
-		delete.lo modify.lo modrdn.lo compare.lo result.lo
+		delete.lo modify.lo modrdn.lo compare.lo result.lo extended.lo
 
 LDAP_INCDIR= ../../../include       
 LDAP_LIBDIR= ../../../libraries
diff --git a/servers/slapd/back-sock/config.c b/servers/slapd/back-sock/config.c
index dc3f1365c..2dcf68bf6 100644
--- a/servers/slapd/back-sock/config.c
+++ b/servers/slapd/back-sock/config.c
@@ -106,6 +106,7 @@ static ConfigOCs osocs[] = {
 #define SOCK_OP_MODRDN	0x020
 #define SOCK_OP_ADD		0x040
 #define SOCK_OP_DELETE	0x080
+#define SOCK_OP_EXTENDED	0x100
 
 #define SOCK_REP_RESULT	0x001
 #define SOCK_REP_SEARCH	0x002
@@ -127,6 +128,7 @@ static slap_verbmasks ov_ops[] = {
 	{ BER_BVC("modrdn"), SOCK_OP_MODRDN },
 	{ BER_BVC("add"), SOCK_OP_ADD },
 	{ BER_BVC("delete"), SOCK_OP_DELETE },
+	{ BER_BVC("extended"), SOCK_OP_EXTENDED },
 	{ BER_BVNULL, 0 }
 };
 
@@ -249,7 +251,9 @@ static BI_op_bind *sockfuncs[] = {
 	sock_back_modify,
 	sock_back_modrdn,
 	sock_back_add,
-	sock_back_delete
+	sock_back_delete,
+	0,                    /* abandon not supported */
+	sock_back_extended
 };
 
 static const int sockopflags[] = {
@@ -260,7 +264,9 @@ static const int sockopflags[] = {
 	SOCK_OP_MODIFY,
 	SOCK_OP_MODRDN,
 	SOCK_OP_ADD,
-	SOCK_OP_DELETE
+	SOCK_OP_DELETE,
+	0,                    /* abandon not supported */
+	SOCK_OP_EXTENDED
 };
 
 static int sock_over_op(
@@ -283,6 +289,7 @@ static int sock_over_op(
 	case LDAP_REQ_MODRDN:	which = op_modrdn; break;
 	case LDAP_REQ_ADD:	which = op_add; break;
 	case LDAP_REQ_DELETE:	which = op_delete; break;
+	case LDAP_REQ_EXTENDED:	which = op_extended; break;
 	default:
 		return SLAP_CB_CONTINUE;
 	}
@@ -365,6 +372,7 @@ sock_over_setup()
 	sockover.on_bi.bi_op_modrdn = sock_over_op;
 	sockover.on_bi.bi_op_add = sock_over_op;
 	sockover.on_bi.bi_op_delete = sock_over_op;
+	sockover.on_bi.bi_extended = sock_over_op;
 	sockover.on_response = sock_over_response;
 
 	sockover.on_bi.bi_cf_ocs = osocs;
diff --git a/servers/slapd/back-sock/extended.c b/servers/slapd/back-sock/extended.c
new file mode 100644
index 000000000..dfe56b32b
--- /dev/null
+++ b/servers/slapd/back-sock/extended.c
@@ -0,0 +1,80 @@
+/* extended.c - sock backend extended routines */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 2000-2017 The OpenLDAP Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+
+#include "portable.h"
+
+#include <stdio.h>
+#include <ac/string.h>
+
+#include "slap.h"
+#include "back-sock.h"
+
+#include "lutil.h"
+
+int
+sock_back_extended( Operation *op, SlapReply *rs )
+{
+	int			rc;
+	struct	sockinfo	*si = (struct sockinfo *) op->o_bd->be_private;
+	FILE		*fp;
+	struct berval b64;
+
+	Debug( LDAP_DEBUG_ARGS, "==> sock_back_extended(%s)\n",
+		op->ore_reqoid.bv_val, op->o_req_dn.bv_val, 0 );
+
+	if ( (fp = opensock( si->si_sockpath )) == NULL ) {
+		send_ldap_error( op, rs, LDAP_OTHER,
+			"could not open socket" );
+		return( -1 );
+	}
+
+	/* write out the request to the extended process */
+	fprintf( fp, "EXTENDED\n" );
+	fprintf( fp, "msgid: %ld\n", (long) op->o_msgid );
+	sock_print_conn( fp, op->o_conn, si );
+	sock_print_suffixes( fp, op->o_bd );
+	fprintf( fp, "oid: %s\n", op->ore_reqoid.bv_val );
+
+  if (op->ore_reqdata) {
+
+		b64.bv_len = LUTIL_BASE64_ENCODE_LEN( op->ore_reqdata->bv_len ) + 1;
+		b64.bv_val = ber_memalloc( b64.bv_len + 1 );
+
+		if( b64.bv_val == NULL ) {
+			return LUTIL_PASSWD_ERR;
+		}
+
+		rc = lutil_b64_ntop(
+			(unsigned char *) op->ore_reqdata->bv_val, op->ore_reqdata->bv_len,
+			b64.bv_val, b64.bv_len );
+
+		b64.bv_len = rc;
+		assert( strlen(b64.bv_val) == b64.bv_len );
+
+		fprintf( fp, "value: %s\n", b64.bv_val );
+
+		ber_memfree( b64.bv_val );
+
+	}
+
+	fprintf( fp, "\n" );
+
+	/* read in the results and send them along */
+	rc = sock_read_and_send_results( op, rs, fp );
+	fclose( fp );
+
+	return( rc );
+}
diff --git a/servers/slapd/back-sock/init.c b/servers/slapd/back-sock/init.c
index dcfe61a44..92e68782f 100644
--- a/servers/slapd/back-sock/init.c
+++ b/servers/slapd/back-sock/init.c
@@ -53,7 +53,7 @@ sock_back_initialize(
 	bi->bi_op_delete = sock_back_delete;
 	bi->bi_op_abandon = 0;
 
-	bi->bi_extended = 0;
+	bi->bi_extended = sock_back_extended;
 
 	bi->bi_chk_referrals = 0;
 
diff --git a/servers/slapd/back-sock/proto-sock.h b/servers/slapd/back-sock/proto-sock.h
index fa02ab896..8b3b5f3ef 100644
--- a/servers/slapd/back-sock/proto-sock.h
+++ b/servers/slapd/back-sock/proto-sock.h
@@ -40,6 +40,8 @@ extern BI_op_modrdn	sock_back_modrdn;
 extern BI_op_add	sock_back_add;
 extern BI_op_delete	sock_back_delete;
 
+extern BI_op_extended	sock_back_extended;
+
 extern int sock_back_init_cf( BackendInfo *bi );
 
 LDAP_END_DECL