diff --git a/src/modules/mc_pos_control/mc_pos_control_main.cpp b/src/modules/mc_pos_control/mc_pos_control_main.cpp
index c24c172af1..bcc3e2ae73 100644
--- a/src/modules/mc_pos_control/mc_pos_control_main.cpp
+++ b/src/modules/mc_pos_control/mc_pos_control_main.cpp
@@ -466,7 +466,7 @@ MulticopterPositionControl::update_ref()
 {
 	if (_local_pos.ref_timestamp != _ref_timestamp) {
 		double lat_sp, lon_sp;
-		float alt_sp;
+		float alt_sp = 0.0f;
 
 		if (_ref_timestamp != 0) {
 			/* calculate current position setpoint in global frame */