diff --git a/src/database.c b/src/database.c
index 66bf1c0..7639e04 100644
--- a/src/database.c
+++ b/src/database.c
@@ -13,7 +13,6 @@
 sqlite3 *db = nullptr;
 pthread_mutex_t db_mutex = PTHREAD_MUTEX_INITIALIZER;
 #else
-FILE *users_file = nullptr;
 pthread_mutex_t users_file_mutex = PTHREAD_MUTEX_INITIALIZER;
 #endif
 
diff --git a/src/database.h b/src/database.h
index 1513eac..da62dda 100644
--- a/src/database.h
+++ b/src/database.h
@@ -7,8 +7,6 @@
 extern sqlite3 *db;
 extern pthread_mutex_t db_mutex;
 #else
-#include <stdio.h>
-extern FILE *users_file;
 extern pthread_mutex_t users_file_mutex;
 #endif
 
diff --git a/src/db_delete_user.c b/src/db_delete_user.c
index c173555..039f997 100644
--- a/src/db_delete_user.c
+++ b/src/db_delete_user.c
@@ -1,15 +1,12 @@
 #include "database.h"
+#include "user.h"
 
 #ifdef USE_SQLITE3
 #include "sql.h"
-#endif
-
-#ifndef USE_SQLITE3
+#else
 #include "file.h"
 #endif
 
-#include "user.h"
-
 bool db_delete_user(const int id) {
 #ifdef USE_SQLITE3
   pthread_mutex_lock(&db_mutex);
diff --git a/src/db_get_all_users.c b/src/db_get_all_users.c
index 9c64856..2471c96 100644
--- a/src/db_get_all_users.c
+++ b/src/db_get_all_users.c
@@ -1,12 +1,9 @@
 #include "database.h"
+#include "user.h"
 
 #ifdef USE_SQLITE3
 #include "sql.h"
-#endif
-
-#include "user.h"
-
-#ifndef USE_SQLITE3
+#else
 #include "file.h"
 #endif
 
diff --git a/src/db_get_user_by_id.c b/src/db_get_user_by_id.c
index e65a0f8..c25a67e 100644
--- a/src/db_get_user_by_id.c
+++ b/src/db_get_user_by_id.c
@@ -1,16 +1,10 @@
-#ifndef USE_SQLITE3
-#include "cJSON.h"
-#endif
-
 #include "database.h"
+#include "user.h"
 
 #ifdef USE_SQLITE3
 #include "sql.h"
-#endif
-
-#include "user.h"
-
-#ifndef USE_SQLITE3
+#else
+#include "cJSON.h"
 #include "file.h"
 #endif
 
diff --git a/src/db_get_user_by_username.c b/src/db_get_user_by_username.c
index 35da766..5dc30a5 100644
--- a/src/db_get_user_by_username.c
+++ b/src/db_get_user_by_username.c
@@ -1,16 +1,10 @@
-#ifndef USE_SQLITE3
-#include "cJSON.h"
-#endif
-
 #include "database.h"
+#include "user.h"
 
 #ifdef USE_SQLITE3
 #include "sql.h"
-#endif
-
-#include "user.h"
-
-#ifndef USE_SQLITE3
+#else
+#include "cJSON.h"
 #include "file.h"
 #endif
 
@@ -75,11 +69,11 @@ User *db_get_user_by_username(const char *username) {
     }
   }
   if (found == nullptr) {
-      pthread_mutex_unlock(&users_file_mutex);
-      // if (user != nullptr) cJSON_Delete(user);
-      cJSON_Delete(users);
-      free(data);
-      return nullptr;
+    pthread_mutex_unlock(&users_file_mutex);
+    // if (user != nullptr) cJSON_Delete(user);
+    cJSON_Delete(users);
+    free(data);
+    return nullptr;
   }
   pthread_mutex_unlock(&users_file_mutex);
   // if (user != nullptr) cJSON_Delete(user);
diff --git a/src/db_get_user_field_by_id.c b/src/db_get_user_field_by_id.c
index c1aeab9..bb74908 100644
--- a/src/db_get_user_field_by_id.c
+++ b/src/db_get_user_field_by_id.c
@@ -1,14 +1,10 @@
 #include <pthread.h>
-
 #include "database.h"
+#include "user.h"
 
 #ifdef USE_SQLITE3
 #include "sql.h"
-#endif
-
-#include "user.h"
-
-#ifndef USE_SQLITE3
+#else
 #include "file.h"
 #endif
 
diff --git a/src/db_insert_user.c b/src/db_insert_user.c
index 6268409..b32f0c2 100644
--- a/src/db_insert_user.c
+++ b/src/db_insert_user.c
@@ -1,16 +1,10 @@
-#ifndef USE_SQLITE3
-#include "cJSON.h"
-#endif
-
 #include "database.h"
+#include "user.h"
 
 #ifdef USE_SQLITE3
 #include "sql.h"
-#endif
-
-#include "user.h"
-
-#ifndef USE_SQLITE3
+#else
+#include "cJSON.h"
 #include "file.h"
 #endif
 
@@ -98,18 +92,12 @@ User *db_insert_user(const char *username, const char *email,
     return nullptr;
   }
   cJSON *new_user_data = cJSON_CreateObject();
-  cJSON *new_user_id = cJSON_CreateNumber(users_size);
-  cJSON *new_user_username = cJSON_CreateString(username);
-  cJSON *new_user_password = cJSON_CreateString(password);
-  cJSON *new_user_email = cJSON_CreateString(email);
-  cJSON *new_user_group = cJSON_CreateString(group);
-  cJSON *new_user_is_superuser = cJSON_CreateBool(is_superuser?1:0);
-  cJSON_AddItemToObject(new_user_data, "id", new_user_id);
-  cJSON_AddItemToObject(new_user_data, "username", new_user_username);
-  cJSON_AddItemToObject(new_user_data, "password", new_user_password);
-  cJSON_AddItemToObject(new_user_data, "email", new_user_email);
-  cJSON_AddItemToObject(new_user_data, "group", new_user_group);
-  cJSON_AddItemToObject(new_user_data, "is_superuser", new_user_is_superuser);
+  cJSON_AddNumberToObject(new_user_data, "id", users_size);
+  cJSON_AddStringToObject(new_user_data, "username", username);
+  cJSON_AddStringToObject(new_user_data, "password", password);
+  cJSON_AddStringToObject(new_user_data, "email", email);
+  cJSON_AddStringToObject(new_user_data, "group", group);
+  cJSON_AddBoolToObject(new_user_data, "is_superuser", *is_superuser);
   char *new_user_data_string = cJSON_Print(new_user_data);
   if (users_size == 0) {
     users = cJSON_CreateArray();
@@ -123,7 +111,8 @@ User *db_insert_user(const char *username, const char *email,
   free(new_data);
   free(data);
   free(new_user_data_string);
-  cJSON_Delete(new_user_data);
+  // cJSON_Delete(new_user_data);
+  cJSON_Delete(users);
   if (user != nullptr) cJSON_Delete(user);
   return return_user;
 #endif
diff --git a/src/db_update_user.c b/src/db_update_user.c
index 260579c..2707dda 100644
--- a/src/db_update_user.c
+++ b/src/db_update_user.c
@@ -1,10 +1,14 @@
-#ifdef USE_SQLITE3
+#include <pthread.h>
 #include "database.h"
-#include "sql.h"
-#endif
-
 #include "user.h"
 
+#ifdef USE_SQLITE3
+#include "sql.h"
+#else
+#include "cJSON.h"
+#include "file.h"
+#endif
+
 User *db_update_user(const int userid, const char *username, const char *email,
                      const char *password, const char *group,
                      const bool *is_superuser) {
@@ -57,7 +61,37 @@ User *db_update_user(const int userid, const char *username, const char *email,
   pthread_mutex_unlock(&db_mutex);
   return new_user(userid, username, email, password, group, is_superuser);
 #else
-  User *asdf = new_user(0, "asdf", "asdf", "asdf", "asdf", false);
-  return asdf;
+  pthread_mutex_lock(&users_file_mutex);
+  char *data = read_file("users_db.json");
+  cJSON *users = cJSON_Parse(data);
+  cJSON *user = nullptr;
+  cJSON_ArrayForEach(user, users) {
+    cJSON *user_id = cJSON_GetObjectItem(user, "id");
+    if (user_id->valueint == userid) {
+      cJSON *user_username = cJSON_GetObjectItem(user, "username");
+      cJSON *user_password = cJSON_GetObjectItem(user, "password");
+      cJSON *user_email = cJSON_GetObjectItem(user, "email");
+      cJSON *user_group = cJSON_GetObjectItem(user, "group");
+      cJSON_SetValuestring(user_username, username);
+      cJSON_SetValuestring(user_password, password);
+      cJSON_SetValuestring(user_email, email);
+      cJSON_SetValuestring(user_group, group);
+      cJSON_DeleteItemFromObject(user, "is_superuser");
+      cJSON_AddBoolToObject(user, "is_superuser", *is_superuser);
+      char *new_data = cJSON_Print(users);
+      write_file("users_db.json", new_data);
+      free(new_data);
+      free(data);
+      cJSON_Delete(users);
+      User *ret =
+          new_user(userid, username, password, email, group, is_superuser);
+      pthread_mutex_unlock(&users_file_mutex);
+      return ret;
+    }
+  }
+  free(data);
+  cJSON_Delete(users);
+  pthread_mutex_unlock(&users_file_mutex);
+  return nullptr;
 #endif
 }
diff --git a/src/db_update_user_field.c b/src/db_update_user_field.c
index 51ea097..7351093 100644
--- a/src/db_update_user_field.c
+++ b/src/db_update_user_field.c
@@ -1,10 +1,13 @@
-#ifdef USE_SQLITE3
 #include "database.h"
-#include "sql.h"
-#endif
-
 #include "user.h"
 
+#ifdef USE_SQLITE3
+#include "sql.h"
+#else
+#include "cJSON.h"
+#include "file.h"
+#endif
+
 bool db_update_user_field(const int id, const char *field, const char *value) {
 #ifdef USE_SQLITE3
   pthread_mutex_lock(&db_mutex);
@@ -37,6 +40,36 @@ bool db_update_user_field(const int id, const char *field, const char *value) {
   pthread_mutex_unlock(&db_mutex);
   return sqlite3_changes(db) > 0;
 #else
-  return 0;
+  pthread_mutex_lock(&users_file_mutex);
+  char *data = read_file("users_db.json");
+  cJSON *users = cJSON_Parse(data);
+  cJSON *user = nullptr;
+  cJSON_ArrayForEach(user, users) {
+    cJSON *user_id = cJSON_GetObjectItem(user, "id");
+    if (user_id->valueint == id) {
+      cJSON *user_field = cJSON_GetObjectItem(user, field);
+      if (cJSON_IsNumber(user_field)) {
+        // cJSON_SetNumberValue(user_field, value);
+        return false;
+      } else if (cJSON_IsBool(user_field)) {
+        // cJSON_DeleteItemFromObject(user, field);
+        // cJSON_AddBoolToObject(user, field, value);
+        return false;
+      } else if (cJSON_IsString(user_field)) {
+        cJSON_SetValuestring(user_field, value);
+      }
+      char *new_data = cJSON_Print(users);
+      write_file("users_db.json", new_data);
+      free(new_data);
+      free(data);
+      cJSON_Delete(users);
+      pthread_mutex_unlock(&users_file_mutex);
+      return true;
+    }
+  }
+  free(data);
+  cJSON_Delete(users);
+  pthread_mutex_unlock(&users_file_mutex);
+  return false;
 #endif
 }
diff --git a/src/register_user.c b/src/register_user.c
index ec3c8bf..5dc9fc3 100644
--- a/src/register_user.c
+++ b/src/register_user.c
@@ -28,7 +28,7 @@ void register_user(struct mg_connection *c, struct mg_http_message *hm) {
   const bool is_superuser_value = is_superuser->valueint ? true : false;
   User *new_user_data = db_insert_user(
       username->valuestring, email->valuestring, password->valuestring,
-      group->valuestring, (const bool *)is_superuser_value);
+      group->valuestring, &is_superuser_value);
   if (new_user_data == nullptr) {
     mg_http_reply(c, 500, HTTP_HEADERS, "{%m:%m}", MG_ESC("error"),
                   MG_ESC("failed to create user"));