diff --git a/src/chat_commands.c b/src/chat_commands.c
index 5d4f43b4c..e15e3bb67 100644
--- a/src/chat_commands.c
+++ b/src/chat_commands.c
@@ -107,7 +107,7 @@ void cmd_cancelfile(WINDOW *window, ToxWindow *self, Tox *tox, int argc, char (*
         return;
     }
 
-    if (!ft) {
+    if (ft == NULL) {
         line_info_add(self, false, NULL, NULL, SYS_MSG, 0, 0, "Invalid file ID.");
         return;
     }
@@ -230,7 +230,12 @@ void cmd_group_accept(WINDOW *window, ToxWindow *self, Tox *tox, int argc, char
 
     if (argc > 0) {
         passwd = argv[1];
-        passwd_len = strlen(passwd);
+        passwd_len = (uint16_t) strlen(passwd);
+    }
+
+    if (passwd_len > TOX_GROUP_MAX_PASSWORD_SIZE) {
+        line_info_add(self, false, NULL, NULL, SYS_MSG, 0, 0, "Failed to join group: Password too long.");
+        return;
     }
 
     size_t nick_len = tox_self_get_name_size(tox);
@@ -244,12 +249,7 @@ void cmd_group_accept(WINDOW *window, ToxWindow *self, Tox *tox, int argc, char
                            (const uint8_t *) passwd, passwd_len, &err);
 
     if (err != TOX_ERR_GROUP_INVITE_ACCEPT_OK) {
-        if (err == TOX_ERR_GROUP_INVITE_ACCEPT_TOO_LONG) {
-            line_info_add(self, false, NULL, NULL, SYS_MSG, 0, 0, "Failed to join group: Password too long.");
-        } else {
-            line_info_add(self, false, NULL, NULL, SYS_MSG, 0, 0, "Failed to join group (error %d).", err);
-        }
-
+        line_info_add(self, false, NULL, NULL, SYS_MSG, 0, 0, "Failed to join group (error %d).", err);
         return;
     }
 
@@ -353,7 +353,7 @@ void cmd_savefile(WINDOW *window, ToxWindow *self, Tox *tox, int argc, char (*ar
 
     FileTransfer *ft = get_file_transfer_struct_index(self->num, idx, FILE_TRANSFER_RECV);
 
-    if (!ft) {
+    if (ft == NULL) {
         line_info_add(self, false, NULL, NULL, SYS_MSG, 0, 0, "No pending file transfers with ID %ld.", idx);
         return;
     }
@@ -443,7 +443,7 @@ void cmd_sendfile(WINDOW *window, ToxWindow *self, Tox *tox, int argc, char (*ar
 
     off_t filesize = file_size(path);
 
-    if (filesize == 0) {
+    if (filesize <= 0) {
         line_info_add(self, false, NULL, NULL, SYS_MSG, 0, 0, "Invalid file.");
         fclose(file_to_send);
         return;
@@ -462,14 +462,14 @@ void cmd_sendfile(WINDOW *window, ToxWindow *self, Tox *tox, int argc, char (*ar
 
     FileTransfer *ft = new_file_transfer(self, self->num, filenum, FILE_TRANSFER_SEND, TOX_FILE_KIND_DATA);
 
-    if (!ft) {
+    if (ft == NULL) {
         err = TOX_ERR_FILE_SEND_TOO_MANY;
         goto on_send_error;
     }
 
     memcpy(ft->file_name, file_name, namelen + 1);
     ft->file = file_to_send;
-    ft->file_size = filesize;
+    ft->file_size = (uint64_t)filesize;
     tox_file_get_file_id(tox, self->num, filenum, ft->file_id, NULL);
 
     char sizestr[32];
diff --git a/src/conference.h b/src/conference.h
index 1076fb3a4..d445302f3 100644
--- a/src/conference.h
+++ b/src/conference.h
@@ -23,6 +23,8 @@
 #ifndef CONFERENCE_H
 #define CONFERENCE_H
 
+#include <time.h>
+
 #include "toxic.h"
 #include "windows.h"
 
diff --git a/src/file_transfers.h b/src/file_transfers.h
index f6e0a341f..3e7482d20 100644
--- a/src/file_transfers.h
+++ b/src/file_transfers.h
@@ -24,6 +24,7 @@
 #define FILE_TRANSFERS_H
 
 #include <limits.h>
+#include <time.h>
 
 #include "notify.h"
 #include "toxic.h"
diff --git a/src/global_commands.c b/src/global_commands.c
index b154d0506..a35e19582 100644
--- a/src/global_commands.c
+++ b/src/global_commands.c
@@ -198,7 +198,7 @@ void cmd_add(WINDOW *window, ToxWindow *self, Tox *tox, int argc, char (*argv)[M
             return;
         }
 
-        id_bin[i] = x;
+        id_bin[i] = (char) x;
     }
 
     if (friend_is_blocked(id_bin)) {
@@ -591,7 +591,7 @@ void cmd_join(WINDOW *window, ToxWindow *self, Tox *tox, int argc, char (*argv)[
             return;
         }
 
-        id_bin[i] = x;
+        id_bin[i] = (char) x;
     }
 
     const char *passwd = NULL;
@@ -599,7 +599,12 @@ void cmd_join(WINDOW *window, ToxWindow *self, Tox *tox, int argc, char (*argv)[
 
     if (argc > 1) {
         passwd = argv[2];
-        passwd_len = strlen(passwd);
+        passwd_len = (uint16_t) strlen(passwd);
+    }
+
+    if (passwd_len > TOX_GROUP_MAX_PASSWORD_SIZE) {
+        line_info_add(self, false, NULL, NULL, SYS_MSG, 0, 0, "Password length cannot exceed %d.", TOX_GROUP_MAX_PASSWORD_SIZE);
+        return;
     }
 
     size_t nick_length = tox_self_get_name_size(tox);
@@ -612,12 +617,7 @@ void cmd_join(WINDOW *window, ToxWindow *self, Tox *tox, int argc, char (*argv)[
                                           (const uint8_t *) passwd, passwd_len, &err);
 
     if (err != TOX_ERR_GROUP_JOIN_OK) {
-        if (err == TOX_ERR_GROUP_JOIN_TOO_LONG) {
-            line_info_add(self, false, NULL, NULL, SYS_MSG, 0, 0, "Password length cannot exceed %d.", TOX_GROUP_MAX_PASSWORD_SIZE);
-        } else {
-            line_info_add(self, false, NULL, NULL, SYS_MSG, 0, 0, "Failed to join group (error %d).", err);
-        }
-
+        line_info_add(self, false, NULL, NULL, SYS_MSG, 0, 0, "Failed to join group (error %d).", err);
         return;
     }
 
diff --git a/src/groupchat_commands.c b/src/groupchat_commands.c
index 2be95e911..b9f132e76 100644
--- a/src/groupchat_commands.c
+++ b/src/groupchat_commands.c
@@ -200,7 +200,7 @@ void cmd_list(WINDOW *window, ToxWindow *self, Tox *tox, int argc, char (*argv)[
 {
     GroupChat *chat = get_groupchat(self->num);
 
-    if (!chat) {
+    if (chat == NULL) {
         line_info_add(self, false, NULL, NULL, SYS_MSG, 0, 0, "Failed to fetch GroupChat object.");
         return;
     }
@@ -857,7 +857,7 @@ void cmd_whois(WINDOW *window, ToxWindow *self, Tox *tox, int argc, char (*argv)
 
     GroupChat *chat = get_groupchat(self->num);
 
-    if (!chat) {
+    if (chat == NULL) {
         line_info_add(self, false, NULL, NULL, SYS_MSG, 0, 0, "Failed to fetch GroupChat object.");
         return;
     }
diff --git a/src/line_info.h b/src/line_info.h
index 64164d5b3..64b5c041f 100644
--- a/src/line_info.h
+++ b/src/line_info.h
@@ -23,6 +23,8 @@
 #ifndef LINE_INFO_H
 #define LINE_INFO_H
 
+#include <time.h>
+
 #include "toxic.h"
 #include "windows.h"