diff --git a/libraries/AP_Baro/AP_Baro_PX4.cpp b/libraries/AP_Baro/AP_Baro_PX4.cpp
index 8847c93f0c..0ddc172fe4 100644
--- a/libraries/AP_Baro/AP_Baro_PX4.cpp
+++ b/libraries/AP_Baro/AP_Baro_PX4.cpp
@@ -24,8 +24,8 @@ AP_Baro_PX4::AP_Baro_PX4(AP_Baro &baro) :
     _num_instances(0)
 {
     memset(instances, 0, sizeof(instances));
-    instances[0].fd = open(BARO_DEVICE_PATH, O_RDONLY);
-    instances[1].fd = open(BARO_DEVICE_PATH"1", O_RDONLY);
+    instances[0].fd = open(BARO_BASE_DEVICE_PATH"0", O_RDONLY);
+    instances[1].fd = open(BARO_BASE_DEVICE_PATH"1", O_RDONLY);
 
     for (uint8_t i=0; i<2; i++) {
         if (instances[i].fd != -1) {