diff --git a/src/samples/demo/zephyr/prj.conf b/src/samples/demo/zephyr/prj.conf
index d5fe8692..86019eb0 100644
--- a/src/samples/demo/zephyr/prj.conf
+++ b/src/samples/demo/zephyr/prj.conf
@@ -16,6 +16,10 @@ CONFIG_DYNAMIC_THREAD_STACK_SIZE=8192
 CONFIG_MAIN_STACK_SIZE=8192
 CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE=-1
 
+# pthreads
+CONFIG_MAX_PTHREAD_MUTEX_COUNT=8
+CONFIG_POSIX_THREAD_THREADS_MAX=8
+
 # Ocre configuration
 CONFIG_OCRE=y
 CONFIG_OCRE_TIMER=y