diff --git a/hal/voice.c b/hal/voice.c
index 5a3ff33..b3645be 100644
--- a/hal/voice.c
+++ b/hal/voice.c
@@ -221,6 +221,13 @@
     uc_info->in_snd_device = SND_DEVICE_NONE;
     uc_info->out_snd_device = SND_DEVICE_NONE;
 
+    if (audio_is_bluetooth_sco_device(uc_info->devices) && !adev->bt_sco_on) {
+        ALOGE("start_call: couldn't find BT SCO, SCO is not ready");
+        adev->voice.in_call = false;
+        ret = -EIO;
+        goto error_start_voice;
+    }
+
     list_add_tail(&adev->usecase_list, &uc_info->list);
 
     select_devices(adev, usecase_id);