diff --git a/src/modules/commander/PreflightCheck.h b/src/modules/commander/PreflightCheck.h
index 4561932328..de8d479813 100644
--- a/src/modules/commander/PreflightCheck.h
+++ b/src/modules/commander/PreflightCheck.h
@@ -79,7 +79,7 @@ const unsigned max_mandatory_accel_count = 1;
 const unsigned max_optional_accel_count = 3;
 
 const unsigned max_mandatory_mag_count = 1;
-const unsigned max_optional_mag_count = 3;
+const unsigned max_optional_mag_count = 4;
 
 const unsigned max_mandatory_baro_count = 1;
 const unsigned max_optional_baro_count = 1;