diff --git a/gen/gen_mpy.py b/gen/gen_mpy.py
index 1867f3a9e..eba7a810b 100644
--- a/gen/gen_mpy.py
+++ b/gen/gen_mpy.py
@@ -1026,7 +1026,7 @@ def register_int_ptr_type(convertor, *types):
 static const mp_lv_obj_type_t mp_lv_{base_obj}_type;
 static const mp_lv_obj_type_t *mp_lv_obj_types[];
 
-static inline const mp_obj_type_t *get_BaseObj_type()
+static inline const mp_obj_type_t *get_BaseObj_type(void)
 {{
     return mp_lv_{base_obj}_type.mp_obj_type;
 }}
@@ -1214,7 +1214,7 @@ def register_int_ptr_type(convertor, *types):
     return mp_lv_obj->callbacks;
 }
 
-static inline const mp_obj_type_t *get_BaseObj_type();
+static inline const mp_obj_type_t *get_BaseObj_type(void);
 
 static void mp_lv_delete_cb(lv_event_t * e)
 {
@@ -1235,10 +1235,10 @@ def register_int_ptr_type(convertor, *types):
     {
         // Find the object type
         const mp_obj_type_t *mp_obj_type = get_BaseObj_type();
-        const lv_obj_class_t *lv_obj_class = lv_obj_get_class(lv_obj);
+        const lv_obj_class_t *lv_obj_cls = lv_obj_get_class(lv_obj);
         const mp_lv_obj_type_t **iter = &mp_lv_obj_types[0];
         for (; *iter; iter++) {
-            if ((*iter)->lv_obj_class == lv_obj_class) {
+            if ((*iter)->lv_obj_class == lv_obj_cls) {
                 mp_obj_type = (*iter)->mp_obj_type;
                 break;
             }
@@ -1345,12 +1345,15 @@ def register_int_ptr_type(convertor, *types):
 int mp_lv_roots_initialized = 0;
 int lvgl_mod_initialized = 0;
 
+/* Prototype definition to make -Werror=missing-prototype happy */
+void mp_lv_log_cb(lv_log_level_t level, const char * buf);
+
 void mp_lv_log_cb(lv_log_level_t level, const char * buf){
 
     mp_printf(&mp_plat_print, buf);
 }
 
-void mp_lv_init_gc()
+void mp_lv_init_gc(void)
 {
     if (!MP_STATE_VM(mp_lv_roots_initialized)) {
         // mp_printf(&mp_plat_print, "[ INIT GC ]");
@@ -1359,7 +1362,7 @@ def register_int_ptr_type(convertor, *types):
     }
 }
 
-void mp_lv_deinit_gc()
+void mp_lv_deinit_gc(void)
 {
 
     // mp_printf(&mp_plat_print, "[ DEINIT GC ]");
@@ -2427,7 +2430,7 @@ def try_generate_struct(struct_name, struct):
  * Struct {struct_name}
  */
 
-static inline const mp_obj_type_t *get_mp_{sanitized_struct_name}_type();
+static inline const mp_obj_type_t *get_mp_{sanitized_struct_name}_type(void);
 
 static inline void* mp_write_ptr_{sanitized_struct_name}(mp_obj_t self_in)
 {{
@@ -2495,7 +2498,7 @@ def try_generate_struct(struct_name, struct):
     parent, &mp_lv_base_struct_type
 );
 
-static inline const mp_obj_type_t *get_mp_{sanitized_struct_name}_type()
+static inline const mp_obj_type_t *get_mp_{sanitized_struct_name}_type(void)
 {{
     return &mp_{sanitized_struct_name}_type;
 }}
diff --git a/lv_conf.h b/lv_conf.h
index d5ad011a8..3da735c1a 100644
--- a/lv_conf.h
+++ b/lv_conf.h
@@ -429,8 +429,8 @@
 
 /*Garbage Collector settings
  *Used if LVGL is bound to higher level language and the memory is managed by that language*/
-extern void mp_lv_init_gc();
-extern void mp_lv_deinit_gc();
+extern void mp_lv_init_gc(void);
+extern void mp_lv_deinit_gc(void);
 #define LV_GC_INIT() mp_lv_init_gc()
 #define LV_GC_DEINIT() mp_lv_deinit_gc()