diff --git a/runtime/starpu/control/runtime_control.c b/runtime/starpu/control/runtime_control.c
index d527cd56b307ad2dc033bf7ecc878a26cddff523..450fecf315ff69f85e62c2b790eb6fee6cfe30a4 100644
--- a/runtime/starpu/control/runtime_control.c
+++ b/runtime/starpu/control/runtime_control.c
@@ -45,7 +45,7 @@ void chameleon_starpu_parallel_worker_init( starpu_sched_opt_t *sched_opt )
         char level[256];
 
         int argc  = strchr( env_pw_level, ':') == NULL ? 1 : 2;
-        int match = sscanf( env_pw_level, "%[^:]:%d", level, &pw_level_number );
+        int match = sscanf( env_pw_level, "%255[^:]:%d", level, &pw_level_number );
 
 #if !defined(CHAMELEON_KERNELS_MT)
         chameleon_warning("chameleon_starpu_parallel_worker_init()", "CHAMELEON has been compiled with multi-threaded kernels disabled (-DCHAMELEON_KERNELS_MT=OFF). This won't break the execution, but you may not obtain the performance gain expected. It is recommended to recompile with -DCHAMELEON_KERNELS_MT=ON.\n");