diff --git a/arch/sim/src/up_touchscreen.c b/arch/sim/src/up_touchscreen.c
index a4c6be1cb5eaf58c9f5352313d4b1d7db763f995..277bfb73994c1592ba14147190cc986ac05c4b75 100644
--- a/arch/sim/src/up_touchscreen.c
+++ b/arch/sim/src/up_touchscreen.c
@@ -128,9 +128,6 @@ static int up_sample(FAR struct up_dev_s *priv,
                           FAR struct up_sample_s *sample);
 static int up_waitsample(FAR struct up_dev_s *priv,
                               FAR struct up_sample_s *sample);
-static int up_transfer(FAR struct up_dev_s *priv, uint8_t cmd);
-static void up_worker(FAR void *arg);
-static int up_interrupt(int irq, FAR void *context);
 
 /* Character driver methods */
 
diff --git a/arch/sim/src/up_x11eventloop.c b/arch/sim/src/up_x11eventloop.c
index a21f895c964311dc1b96f290ab06667c923a0e25..5c449b7391d5e24147b2d52e118f9a31a73512f0 100644
--- a/arch/sim/src/up_x11eventloop.c
+++ b/arch/sim/src/up_x11eventloop.c
@@ -129,7 +129,7 @@ static void *up_x11eventthread(void *arg)
   if (ret != GrabSuccess)
     {
       fprintf(stderr, "Failed grap pointer\n");
-      return -1;
+      return NULL;
     }
 
   /* Then loop forever, waiting for events and processing events as they are