diff --git a/launch/mavros_posix_sitl.launch b/launch/mavros_posix_sitl.launch
index 408122c9c8..6590d20a8b 100644
--- a/launch/mavros_posix_sitl.launch
+++ b/launch/mavros_posix_sitl.launch
@@ -14,7 +14,7 @@
     <arg name="vehicle" default="iris"/>
     <arg name="world" default="$(find mavlink_sitl_gazebo)/worlds/empty.world"/>
     <arg name="sdf" default="$(find mavlink_sitl_gazebo)/models/$(arg vehicle)/$(arg vehicle).sdf"/>
-    <arg name="rcS" default="$(find px4)/posix-configs/SITL/init/rcS"/>
+    <arg name="rcS" default="$(find px4)/posix-configs/SITL/init/$(arg est)/$(arg vehicle)"/>
 
     <!-- gazebo configs -->
     <arg name="gui" default="true"/>
diff --git a/launch/posix_sitl.launch b/launch/posix_sitl.launch
index 4a8d00ceca..b112a72dec 100644
--- a/launch/posix_sitl.launch
+++ b/launch/posix_sitl.launch
@@ -14,7 +14,7 @@
     <arg name="vehicle" default="iris"/>
     <arg name="world" default="$(find mavlink_sitl_gazebo)/worlds/empty.world"/>
     <arg name="sdf" default="$(find mavlink_sitl_gazebo)/models/$(arg vehicle)/$(arg vehicle).sdf"/>
-    <arg name="rcS" default="$(find px4)/posix-configs/SITL/init/rcS"/>
+    <arg name="rcS" default="$(find px4)/posix-configs/SITL/init/$(arg est)/$(arg vehicle)"/>
 
     <!-- gazebo configs -->
     <arg name="gui" default="true"/>
@@ -28,7 +28,7 @@
     <arg unless="$(arg interactive)" name="px4_command_arg1" value="-d"/>
     <arg     if="$(arg interactive)" name="px4_command_arg1" value=""/>
     <node name="sitl" pkg="px4" type="px4" output="screen"
-	    args="$(arg rootfs) $(arg rcS) $(arg px4_command_arg1)" />
+        args="$(find px4)/ROMFS/px4fmu_common -s $(arg rcS) $(arg px4_command_arg1)" required="true"/>
 
     <!-- Gazebo sim -->
     <include file="$(find gazebo_ros)/launch/empty_world.launch">
@@ -41,7 +41,6 @@
     </include>
     <!-- gazebo model -->
     <node name="$(anon vehicle_spawn)" pkg="gazebo_ros" type="spawn_model" output="screen" args="-sdf -file $(arg sdf) -model $(arg vehicle) -x $(arg x) -y $(arg y) -z $(arg z) -R $(arg R) -P $(arg P) -Y $(arg Y)"/>
-</launch>
 
     <!-- This will set the environment variable needed to select iris in the startup. -->
     <machine name="px4" env-loader="iris_env.sh" address="none" />
diff --git a/launch/single_vehicle_spawn.launch b/launch/single_vehicle_spawn.launch
index c2f8bc5e39..3dc92ef5f5 100644
--- a/launch/single_vehicle_spawn.launch
+++ b/launch/single_vehicle_spawn.launch
@@ -23,7 +23,7 @@
     <!-- PX4 SITL -->
     <arg unless="$(arg interactive)" name="px4_command_arg1" value=""/>
     <arg     if="$(arg interactive)" name="px4_command_arg1" value="-d"/>
-    <node name="sitl_$(arg ID)" pkg="px4" type="px4" output="screen" args="$(find px4) -s $(arg rcS) -i $(arg ID) $(arg px4_command_arg1)">
+    <node name="sitl_$(arg ID)" pkg="px4" type="px4" output="screen" args="$(find px4)/ROMFS/px4fmu_common -s $(arg rcS) -i $(arg ID) $(arg px4_command_arg1)">
     </node>
     <!-- spawn vehicle -->
     <node name="$(arg vehicle)_$(arg ID)_spawn" output="screen" pkg="gazebo_ros" type="spawn_model" args="-urdf -param rotors_description -model $(arg vehicle)_$(arg ID) -package_to_model -x $(arg x) -y $(arg y) -z $(arg z) -R $(arg R) -P $(arg P) -Y $(arg Y)"/>