diff --git a/ROMFS/px4fmu_common/init.d-posix/rc.replay b/ROMFS/px4fmu_common/init.d-posix/rc.replay
new file mode 100644
index 0000000000..58a0ca9658
--- /dev/null
+++ b/ROMFS/px4fmu_common/init.d-posix/rc.replay
@@ -0,0 +1,18 @@
+#!/usr/bin/bash
+
+# EKF2 replay script
+
+publisher_rules_file="orb_publisher.rules"
+cat <<EOF > "$publisher_rules_file"
+restrict_topics: sensor_combined, vehicle_gps_position, vehicle_land_detected
+module: replay
+ignore_others: false
+EOF
+
+uorb start
+param set SDLOG_DIRS_MAX 7
+
+ekf2 start -r
+logger start -f -t -b 1000 -p vehicle_attitude
+sleep 0.2
+replay start
diff --git a/ROMFS/px4fmu_common/init.d-posix/rcS b/ROMFS/px4fmu_common/init.d-posix/rcS
index 6db67e9a4d..00a4685b88 100644
--- a/ROMFS/px4fmu_common/init.d-posix/rcS
+++ b/ROMFS/px4fmu_common/init.d-posix/rcS
@@ -4,6 +4,17 @@
 # (px4-alias.sh is expected to be in the PATH)
 source px4-alias.sh
 
+# Main SITL startup script
+
+
+# check for ekf2 replay
+if [ "$replay_mode" == "ekf2" ]
+then
+	sh etc/init.d-posix/rc.replay
+	exit 0
+fi
+
+
 # TODO: In the future we want to share rc.autostart with NuttX
 #source rc.autostart
 
@@ -119,11 +130,11 @@ mc_att_control start
 #       infrastructure already available on NuttX.
 if param compare SYS_AUTOSTART 10016
 then
-	source etc/init.d-posix/10016_iris
+	sh etc/init.d-posix/10016_iris
 
 elif param compare SYS_AUTOSTART 6011
 then
-	source etc/init.d-posix/6011_typhoon_h480
+	sh etc/init.d-posix/6011_typhoon_h480
 fi
 
 
diff --git a/Tools/sitl_run.sh b/Tools/sitl_run.sh
index 1b84083c97..a8e9047a02 100755
--- a/Tools/sitl_run.sh
+++ b/Tools/sitl_run.sh
@@ -36,19 +36,6 @@ then
 	model="iris"
 fi
 
-# check replay mode
-if [ "$replay_mode" == "ekf2" ]
-then
-	model="iris_replay"
-	# create the publisher rules
-	publisher_rules_file="$rootfs/orb_publisher.rules"
-	cat <<EOF > "$publisher_rules_file"
-restrict_topics: sensor_combined, vehicle_gps_position, vehicle_land_detected
-module: replay
-ignore_others: false
-EOF
-fi
-
 if [ "$#" -lt 7 ]
 then
 	echo usage: sitl_run.sh sitl_bin rcS_path debugger program model src_path build_path
diff --git a/platforms/posix/src/px4-alias.sh_in b/platforms/posix/src/px4-alias.sh_in
index bd79461192..5d806f8f4f 100644
--- a/platforms/posix/src/px4-alias.sh_in
+++ b/platforms/posix/src/px4-alias.sh_in
@@ -15,6 +15,15 @@ set() {
 # alternative method with an alias:
 # alias set='f(){ set -- "$1=$2"; eval "$1"; unset -f f; }; eval f'
 
+# Execute another shell script.
+# $1: Path to the script, (optionally starts with /, to match with the NuttX
+# scripts)
+sh() {
+	script="$1"
+	[[ "$script" != /* ]] && script="/$script"
+	source "$(pwd)$script"
+}
+
 # Don't stop on errors.
 #set -e
 
diff --git a/posix-configs/SITL/init/ekf2/iris_replay b/posix-configs/SITL/init/ekf2/iris_replay
deleted file mode 100644
index aac625fb5e..0000000000
--- a/posix-configs/SITL/init/ekf2/iris_replay
+++ /dev/null
@@ -1,13 +0,0 @@
-#!/usr/bin/bash
-# PX4 commands need the 'px4-' prefix in bash.
-# (px4-alias.sh is expected to be in the PATH)
-source px4-alias.sh
-
-uorb start
-param set SDLOG_DIRS_MAX 7
-
-ekf2 start -r
-logger start -f -t -b 1000 -p vehicle_attitude
-sleep 0.2
-replay start
-