diff --git a/configure.ac b/configure.ac
index e6a636f..41c3311 100644
--- a/configure.ac
+++ b/configure.ac
@@ -5,17 +5,6 @@ AC_CONFIG_SRCDIR([cwmp.c])
 AM_INIT_AUTOMAKE([-Wall -Werror foreign subdir-objects])
 
 # additional options
-
-AC_ARG_ENABLE(acs, [AS_HELP_STRING([--enable-acs],
-	[specify which ACS is going to be used; there are some optimizations available for HDM and Fusion ACS (default --enable-acs=multi]))],,
-	[AC_DEFINE(ACS_MULTI)])
-
-AS_IF([test "x$enable_acs" = "xhdm"], [AC_DEFINE(ACS_HDM)])
-AS_IF([test "x$enable_acs" = "xfusion"], [AC_DEFINE(ACS_FUSION)])
-AS_IF([test "x$enable_acs" = "xmulti"], [AC_DEFINE(ACS_MULTI)])
-AS_IF([test "x$enable_acs" = "xyes"], [AC_DEFINE(ACS_MULTI)])
-AS_IF([test "x$enable_acs" = "xno"], [AC_DEFINE(ACS_MULTI)])
-
 AC_ARG_ENABLE(libopenssl, [AS_HELP_STRING([--enable-libopenssl], [enable libopenssl feature])], AC_DEFINE(LOPENSSL))
 AM_CONDITIONAL([LOPENSSL],[test "x$enable_libopenssl" = "xyes"])
 
diff --git a/gitlab-ci/shared.sh b/gitlab-ci/shared.sh
index ad05f20..d9654c4 100644
--- a/gitlab-ci/shared.sh
+++ b/gitlab-ci/shared.sh
@@ -121,7 +121,7 @@ function build_icwmp()
 
 	# compile icwmp
 	autoreconf -i >/dev/null 2>&1
-	./configure CFLAGS="$COV_CFLAGS" LDFLAGS="$COV_LDFLAGS" --enable-acs=multi --enable-debug --enable-libopenssl >/dev/null 2>&1
+	./configure CFLAGS="$COV_CFLAGS" LDFLAGS="$COV_LDFLAGS" --enable-libopenssl >/dev/null 2>&1
 	make CFLAGS="$COV_CFLAGS" LDFLAGS="$COV_LDFLAGS"
 	check_ret $?
 }
diff --git a/http.c b/http.c
index 6340113..23dd46f 100644
--- a/http.c
+++ b/http.c
@@ -157,11 +157,7 @@ int http_send_message(struct cwmp *cwmp, char *msg_out, int msg_out_len, char **
 	http_c.header_list = curl_slist_append(http_c.header_list, "Content-Type: text/xml");
 	if (!http_c.header_list)
 		return -1;
-#ifdef ACS_FUSION
-	http_c.header_list = curl_slist_append(http_c.header_list, "Expect:");
-	if (!http_c.header_list)
-		return -1;
-#endif /* ACS_FUSION */
+
 	if (cwmp->conf.http_disable_100continue) {
 		http_c.header_list = curl_slist_append(http_c.header_list, "Expect:");
 		if (!http_c.header_list)
diff --git a/rpc_soap.c b/rpc_soap.c
index 5c551aa..14e9c51 100755
--- a/rpc_soap.c
+++ b/rpc_soap.c
@@ -242,9 +242,7 @@ create_value:
 	if (!b)
 		return -1;
 
-#ifdef ACS_MULTI
 	mxmlElementSetAttr(b, "xsi:type", (dm_parameter->type && dm_parameter->type[0] != '\0') ? dm_parameter->type : "xsd:string");
-#endif
 	b = mxmlNewOpaque(b, dm_parameter->value);
 	if (!b)
 		return -1;
@@ -927,9 +925,7 @@ int cwmp_handle_rpc_cpe_get_parameter_values(struct session *session, struct rpc
 	mxml_node_t *n, *parameter_list, *b;
 	char *parameter_name = NULL;
 	int counter = 0, fault_code = FAULT_CPE_INTERNAL_ERROR;
-#ifdef ACS_MULTI
 	char c[256] = {0};
-#endif
 	LIST_HEAD(parameters_list);
 
 	b = session->body_in;
@@ -948,9 +944,7 @@ int cwmp_handle_rpc_cpe_get_parameter_values(struct session *session, struct rpc
 	if (!parameter_list)
 		goto fault;
 
-#ifdef ACS_MULTI
 	mxmlElementSetAttr(parameter_list, "xsi:type", "soap_enc:Array");
-#endif
 	while (b) {
 		const char *node_value = mxmlGetOpaque(b);
 		const char *node_name = (char *) mxmlGetElement(b);
@@ -999,10 +993,7 @@ int cwmp_handle_rpc_cpe_get_parameter_values(struct session *session, struct rpc
 				if (!n)
 					goto fault;
 
-#ifdef ACS_MULTI
 				mxmlElementSetAttr(n, "xsi:type", param_value->type ? param_value->type : "");
-#endif
-
 				n = mxmlNewOpaque(n, param_value->value ? param_value->value : "");
 				if (!n)
 					goto fault;
@@ -1015,7 +1006,6 @@ int cwmp_handle_rpc_cpe_get_parameter_values(struct session *session, struct rpc
 		b = mxmlWalkNext(b, session->body_in, MXML_DESCEND);
 	}
 
-#ifdef ACS_MULTI
 	b = mxmlFindElement(session->tree_out, session->tree_out, "ParameterList", NULL, NULL, MXML_DESCEND);
 	if (!b)
 		goto fault;
@@ -1024,8 +1014,6 @@ int cwmp_handle_rpc_cpe_get_parameter_values(struct session *session, struct rpc
 		goto fault;
 
 	mxmlElementSetAttr(b, "soap_enc:arrayType", c);
-#endif
-
 	return 0;
 
 fault:
@@ -1045,9 +1033,8 @@ int cwmp_handle_rpc_cpe_get_parameter_names(struct session *session, struct rpc
 	char *NextLevel = NULL;
 	int counter = 0, fault_code = FAULT_CPE_INTERNAL_ERROR;
 	LIST_HEAD(parameters_list);
-#ifdef ACS_MULTI
 	char c[256] = {0};
-#endif
+
 	if (session->tree_out == NULL)
 		goto fault;
 
@@ -1063,9 +1050,7 @@ int cwmp_handle_rpc_cpe_get_parameter_names(struct session *session, struct rpc
 	if (!parameter_list)
 		goto fault;
 
-#ifdef ACS_MULTI
 	mxmlElementSetAttr(parameter_list, "xsi:type", "soap_enc:Array");
-#endif
 
 	while (b) {
 		const char *node_value = mxmlGetOpaque(b);
@@ -1135,7 +1120,6 @@ int cwmp_handle_rpc_cpe_get_parameter_names(struct session *session, struct rpc
 		counter++;
 	}
 	cwmp_free_all_dm_parameter_list(&parameters_list);
-#ifdef ACS_MULTI
 	b = mxmlFindElement(session->tree_out, session->tree_out, "ParameterList", NULL, NULL, MXML_DESCEND);
 	if (!b)
 		goto fault;
@@ -1144,7 +1128,6 @@ int cwmp_handle_rpc_cpe_get_parameter_names(struct session *session, struct rpc
 		goto fault;
 
 	mxmlElementSetAttr(b, "soap_enc:arrayType", c);
-#endif
 	return 0;
 
 fault:
@@ -1164,9 +1147,8 @@ int cwmp_handle_rpc_cpe_get_parameter_attributes(struct session *session, struct
 	char *parameter_name = NULL;
 	int counter = 0, fault_code = FAULT_CPE_INTERNAL_ERROR;
 	LIST_HEAD(parameters_list);
-#ifdef ACS_MULTI
 	char c[256];
-#endif
+
 	b = session->body_in;
 	n = mxmlFindElement(session->tree_out, session->tree_out, "soap_env:Body", NULL, NULL, MXML_DESCEND);
 	if (!n)
@@ -1180,9 +1162,7 @@ int cwmp_handle_rpc_cpe_get_parameter_attributes(struct session *session, struct
 	if (!parameter_list)
 		goto fault;
 
-#ifdef ACS_MULTI
 	mxmlElementSetAttr(parameter_list, "xsi:type", "soap_enc:Array");
-#endif
 
 	while (b) {
 		const char *node_opaque = mxmlGetOpaque(b);
@@ -1250,7 +1230,6 @@ int cwmp_handle_rpc_cpe_get_parameter_attributes(struct session *session, struct
 		}
 		b = mxmlWalkNext(b, session->body_in, MXML_DESCEND);
 	}
-#ifdef ACS_MULTI
 	b = mxmlFindElement(session->tree_out, session->tree_out, "ParameterList", NULL, NULL, MXML_DESCEND);
 	if (!b)
 		goto fault;
@@ -1259,7 +1238,6 @@ int cwmp_handle_rpc_cpe_get_parameter_attributes(struct session *session, struct
 		goto fault;
 
 	mxmlElementSetAttr(b, "soap_enc:arrayType", c);
-#endif
 	return 0;
 
 fault:
@@ -1700,10 +1678,8 @@ int cwmp_handle_rpc_cpe_get_rpc_methods(struct session *session, struct rpc *rpc
 {
 	mxml_node_t *n, *method_list;
 	int i, counter = 0;
-#ifdef ACS_MULTI
 	mxml_node_t *b = session->body_in;
 	char c[128];
-#endif
 
 	n = mxmlFindElement(session->tree_out, session->tree_out, "soap_env:Body", NULL, NULL, MXML_DESCEND);
 	if (!n)
@@ -1730,7 +1706,7 @@ int cwmp_handle_rpc_cpe_get_rpc_methods(struct session *session, struct rpc *rpc
 			counter++;
 		}
 	}
-#ifdef ACS_MULTI
+
 	b = mxmlFindElement(session->tree_out, session->tree_out, "MethodList", NULL, NULL, MXML_DESCEND);
 	if (!b)
 		goto fault;
@@ -1740,7 +1716,6 @@ int cwmp_handle_rpc_cpe_get_rpc_methods(struct session *session, struct rpc *rpc
 		goto fault;
 
 	mxmlElementSetAttr(b, "soap_enc:arrayType", c);
-#endif
 
 	return 0;
 
diff --git a/xml.c b/xml.c
index b75d777..178e64a 100644
--- a/xml.c
+++ b/xml.c
@@ -381,9 +381,8 @@ static int xml_prepare_lwnotifications(mxml_node_t *parameter_list)
 		b = mxmlNewElement(n, "Value");
 		if (!b)
 			goto error;
-#ifdef ACS_MULTI
+
 		mxmlElementSetAttr(b, "xsi:type", lw_notification->type);
-#endif
 		b = mxmlNewOpaque(b, lw_notification->value);
 		if (!b)
 			goto error;