diff --git a/movement/movement.c b/movement/movement.c
index 0b292a1..cb3dcf7 100644
--- a/movement/movement.c
+++ b/movement/movement.c
@@ -319,11 +319,11 @@ void movement_request_wake() {
     _movement_reset_inactivity_countdown();
 }
 
-void end_buzzing() {
+static void end_buzzing() {
     movement_state.is_buzzing = false;
 }
 
-void end_buzzing_and_disable_buzzer(void) {
+static void end_buzzing_and_disable_buzzer(void) {
     end_buzzing();
     watch_disable_buzzer();
 }
diff --git a/movement/shell.c b/movement/shell.c
index 8f146e5..3782068 100644
--- a/movement/shell.c
+++ b/movement/shell.c
@@ -30,6 +30,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <string.h>
+#include <stdlib.h>
 
 #if __EMSCRIPTEN__
 #include <emscripten.h>
@@ -57,7 +58,7 @@ static char *prv_skip_whitespace(char *c) {
         if (*c == 0) {
             return NULL;
         }
-        if (!isspace((int) *c) != 0) {
+        if ((!isspace((int) *c)) != 0) {
             return c;
         }
         c++;