diff --git a/tools/cooja/contiki_tests/sky_shell_exec_serial.csc b/tools/cooja/contiki_tests/sky_shell_exec_serial.csc
index 3218742cb..65d5700a4 100644
--- a/tools/cooja/contiki_tests/sky_shell_exec_serial.csc
+++ b/tools/cooja/contiki_tests/sky_shell_exec_serial.csc
@@ -21,12 +21,17 @@
       <identifier>sky1</identifier>
       <description>Sky Mote Type #sky1</description>
       <source>../../../examples/sky-shell-exec/sky-shell-exec.c</source>
-      <commands>echo COMPILING CONTIKI EXECUTABLE
+      <commands>echo CLEANING
+make clean TARGET=sky
+
+echo COMPILING CONTIKI EXECUTABLE
 make hello-world.ce TARGET=sky
 
 echo COMPILING FIRMWARE WITH CORE
 make sky-shell-exec.sky TARGET=sky
 make sky-shell-exec.sky CORE=sky-shell-exec.sky TARGET=sky
+make sky-shell-exec.sky CORE=sky-shell-exec.sky TARGET=sky
+make sky-shell-exec.sky CORE=sky-shell-exec.sky TARGET=sky
 make sky-shell-exec.sky CORE=sky-shell-exec.sky TARGET=sky</commands>
       <firmware>../../../examples/sky-shell-exec/sky-shell-exec.sky</firmware>
       <moteinterface>se.sics.cooja.interfaces.Position</moteinterface>