diff --git a/tester/dtmf_tester.c b/tester/dtmf_tester.c
index 8cfebe769..2d8068e87 100644
--- a/tester/dtmf_tester.c
+++ b/tester/dtmf_tester.c
@@ -19,10 +19,6 @@
 #include "liblinphone_tester.h"
 #include "private.h"
 
-LinphoneCoreManager* marie;
-LinphoneCoreManager* pauline;
-LinphoneCall *marie_call;
-
 void dtmf_received(LinphoneCore *lc, LinphoneCall *call, int dtmf) {
 	stats* counters = get_stats(lc);
 	char** dst = &counters->dtmf_list_received;
@@ -32,11 +28,12 @@ void dtmf_received(LinphoneCore *lc, LinphoneCall *call, int dtmf) {
 	counters->dtmf_count++;
 }
 
-void send_dtmf_base(bool_t use_rfc2833, bool_t use_sipinfo, char dtmf, char* dtmf_seq, bool_t use_opus) {
+void send_dtmf_base(LinphoneCoreManager **pmarie, LinphoneCoreManager **ppauline, bool_t use_rfc2833, bool_t use_sipinfo, char dtmf, char* dtmf_seq, bool_t use_opus) {
 	char* expected = NULL;
 	int dtmf_count_prev;
-	marie = linphone_core_manager_new( "marie_rc");
-	pauline = linphone_core_manager_new( "pauline_tcp_rc");
+	LinphoneCoreManager *marie = *pmarie = linphone_core_manager_new( "marie_rc");
+	LinphoneCoreManager *pauline = *ppauline = linphone_core_manager_new( "pauline_tcp_rc");
+	LinphoneCall *marie_call = NULL;
 
 	if (use_opus) {
 		if (!ms_filter_codec_supported("opus")) {
@@ -90,7 +87,8 @@ void send_dtmf_base(bool_t use_rfc2833, bool_t use_sipinfo, char dtmf, char* dtm
 	}
 }
 
-void send_dtmf_cleanup() {
+void send_dtmf_cleanup(LinphoneCoreManager *marie, LinphoneCoreManager *pauline) {
+	LinphoneCall *marie_call = linphone_core_get_current_call(marie->lc);
 	if (marie_call) {
 		BC_ASSERT_PTR_NULL(marie_call->dtmfs_timer);
 		BC_ASSERT_PTR_NULL(marie_call->dtmf_sequence);
@@ -105,52 +103,62 @@ void send_dtmf_cleanup() {
 }
 
 static void send_dtmf_rfc2833() {
-	send_dtmf_base(TRUE,FALSE,'1',NULL,FALSE);
-	send_dtmf_cleanup();
+	LinphoneCoreManager *marie, *pauline;
+	send_dtmf_base(&marie, &pauline, TRUE,FALSE,'1',NULL,FALSE);
+	send_dtmf_cleanup(marie, pauline);
 }
 
 static void send_dtmf_sip_info() {
-	send_dtmf_base(FALSE,TRUE,'#',NULL,FALSE);
-	send_dtmf_cleanup();
+	LinphoneCoreManager *marie, *pauline;
+	send_dtmf_base(&marie, &pauline, FALSE,TRUE,'#',NULL,FALSE);
+	send_dtmf_cleanup(marie, pauline);
 }
 
 static void send_dtmfs_sequence_rfc2833() {
-	send_dtmf_base(TRUE,FALSE,'\0',"1230#",FALSE);
-	send_dtmf_cleanup();
+	LinphoneCoreManager *marie, *pauline;
+	send_dtmf_base(&marie, &pauline, TRUE,FALSE,'\0',"1230#",FALSE);
+	send_dtmf_cleanup(marie, pauline);
 }
 
 static void send_dtmfs_sequence_sip_info() {
-	send_dtmf_base(FALSE,TRUE,'\0',"1230#",FALSE);
-	send_dtmf_cleanup();
+	LinphoneCoreManager *marie, *pauline;
+	send_dtmf_base(&marie, &pauline, FALSE,TRUE,'\0',"1230#",FALSE);
+	send_dtmf_cleanup(marie, pauline);
 }
 
 static void send_dtmfs_sequence_not_ready() {
+	LinphoneCoreManager *marie;
 	marie = linphone_core_manager_new( "marie_rc");
 	BC_ASSERT_EQUAL(linphone_call_send_dtmfs(linphone_core_get_current_call(marie->lc), "123"), -1, int, "%d");
 	linphone_core_manager_destroy(marie);
 }
 
 static void send_dtmfs_sequence_call_state_changed() {
-	send_dtmf_base(FALSE,TRUE,'\0',NULL,FALSE);
+	LinphoneCoreManager *marie, *pauline;
+	LinphoneCall *marie_call = NULL;
+	send_dtmf_base(&marie, &pauline, FALSE,TRUE,'\0',NULL,FALSE);
 
-	/*very long DTMF(around 4 sec to be sent)*/
-	linphone_call_send_dtmfs(marie_call, "123456789123456789");
-	/*just after, change call state, and expect DTMF to be canceled*/
-	linphone_core_pause_call(marie_call->core,marie_call);
-	BC_ASSERT_TRUE(wait_for(marie->lc,pauline->lc,&marie->stat.number_of_LinphoneCallPausing,1));
-	BC_ASSERT_TRUE(wait_for(marie->lc,pauline->lc,&marie->stat.number_of_LinphoneCallPaused,1));
+	marie_call = linphone_core_get_current_call(marie->lc);
+	if (marie_call) {
+		/*very long DTMF(around 4 sec to be sent)*/
+		linphone_call_send_dtmfs(marie_call, "123456789123456789");
+		/*just after, change call state, and expect DTMF to be canceled*/
+		linphone_core_pause_call(marie_call->core,marie_call);
+		BC_ASSERT_TRUE(wait_for(marie->lc,pauline->lc,&marie->stat.number_of_LinphoneCallPausing,1));
+		BC_ASSERT_TRUE(wait_for(marie->lc,pauline->lc,&marie->stat.number_of_LinphoneCallPaused,1));
 
-	/*wait a few time to ensure that no DTMF are received*/
-	wait_for_until(marie->lc, pauline->lc, NULL, 0, 1000);
+		/*wait a few time to ensure that no DTMF are received*/
+		wait_for_until(marie->lc, pauline->lc, NULL, 0, 1000);
 
-	BC_ASSERT_PTR_NULL(pauline->stat.dtmf_list_received);
-
-	send_dtmf_cleanup();
+		BC_ASSERT_PTR_NULL(pauline->stat.dtmf_list_received);
+	}
+	send_dtmf_cleanup(marie, pauline);
 }
 
 static void send_dtmf_rfc2833_opus() {
-	send_dtmf_base(TRUE,FALSE,'1',NULL,TRUE);
-	send_dtmf_cleanup();
+	LinphoneCoreManager *marie, *pauline;
+	send_dtmf_base(&marie, &pauline, TRUE,FALSE,'1',NULL,TRUE);
+	send_dtmf_cleanup(marie, pauline);
 }
 
 test_t dtmf_tests[] = {