diff --git a/account.c b/account.cpp
similarity index 96%
rename from account.c
rename to account.cpp
index a34a550..a15e3be 100644
--- a/account.c
+++ b/account.cpp
@@ -16,10 +16,10 @@
 #include "config.hh"
 #include "input.h"
 #include "omemo.h"
-#include "account.h"
+#include "account.hh"
 #include "connection.h"
-#include "user.h"
-#include "channel.h"
+#include "user.hh"
+#include "channel.hh"
 #include "buffer.h"
 
 struct t_account *accounts = NULL;
@@ -116,7 +116,7 @@ void account__add_device(struct t_account *account,
     new_device = account__search_device(account, device->id);
     if (!new_device)
     {
-        new_device = malloc(sizeof(*new_device));
+        new_device = (struct t_account_device*)malloc(sizeof(*new_device));
         new_device->id = device->id;
         new_device->name = strdup(device->name);
         new_device->label = device->label ? strdup(device->label) : NULL;
@@ -177,14 +177,14 @@ xmpp_stanza_t *account__get_devicelist(struct t_account *account)
     char id[64] = {0};
     int i = 0;
 
-    device = malloc(sizeof(struct t_account_device));
+    device = (struct t_account_device*)malloc(sizeof(struct t_account_device));
 
     device->id = account->omemo->device_id;
     snprintf(id, sizeof(id), "%u", device->id);
     device->name = strdup(id);
     device->label = strdup("weechat");
 
-    children = malloc(sizeof(xmpp_stanza_t *) * 128);
+    children = (xmpp_stanza_t **)malloc(sizeof(xmpp_stanza_t *) * 128);
     children[i++] = stanza__iq_pubsub_publish_item_list_device(
         account->context, NULL, with_noop(device->name), NULL);
 
@@ -231,7 +231,7 @@ struct t_account_mam_query *account__add_mam_query(struct t_account *account,
 
     if (!(mam_query = account__mam_query_search(account, id)))
     {
-        mam_query = malloc(sizeof(struct t_account_mam_query));
+        mam_query = (struct t_account_mam_query*)malloc(sizeof(struct t_account_mam_query));
         mam_query->id = strdup(id);
         mam_query->with = strdup(channel->id);
 
@@ -321,7 +321,7 @@ void account__log_emit_weechat(void *const userdata, const xmpp_log_level_t leve
     const char *tags = level > XMPP_LEVEL_DEBUG ? "no_log" : NULL;
 
     char *xml;
-    if ((level == XMPP_LEVEL_DEBUG) && ((xml = strchr(msg, '<')) != NULL))
+    if ((level == XMPP_LEVEL_DEBUG) && ((xml = const_cast<char*>(strchr(msg, '<'))) != NULL))
     {
         FILE *nullfd = fopen("/dev/null", "w+");
         xmlGenericErrorContext = nullfd;
@@ -350,7 +350,7 @@ void account__log_emit_weechat(void *const userdata, const xmpp_log_level_t leve
         {
             colour = weechat_color("red");
         }
-        xmlChar *buf = malloc(strlen(xml) * 2);
+        xmlChar *buf = (xmlChar*)malloc(strlen(xml) * 2);
         if (buf == NULL) {
             weechat_printf(
                 account ? account->buffer : NULL,
@@ -407,7 +407,7 @@ struct t_account *account__alloc(const char *name)
         return NULL;
 
     /* alloc memory for new account */
-    new_account = malloc(sizeof(*new_account));
+    new_account = (struct t_account*)malloc(sizeof(*new_account));
     if (!new_account)
     {
         weechat_printf(NULL,
@@ -466,7 +466,7 @@ struct t_account *account__alloc(const char *name)
             strlen(account_options[i][0]) +
             512 +  /* inherited option name(xmpp.account_default.xxx) */
             1;
-        option_name = malloc(length);
+        option_name = (char*)malloc(length);
         if (option_name)
         {
             snprintf(option_name, length, "%s.%s << xmpp.account_default.%s",
@@ -702,7 +702,7 @@ struct t_gui_buffer *account__create_buffer(struct t_account *account)
     weechat_buffer_set(account->buffer, "nicklist", "1");
     weechat_buffer_set(account->buffer, "nicklist_display_groups", "0");
     weechat_buffer_set_pointer(account->buffer, "nicklist_callback",
-                               &buffer__nickcmp_cb);
+                               (void*)&buffer__nickcmp_cb);
     weechat_buffer_set_pointer(account->buffer, "nicklist_callback_pointer",
                                account);
 
diff --git a/account.h b/account.hh
similarity index 93%
rename from account.h
rename to account.hh
index 321afd4..aa1a2e5 100644
--- a/account.h
+++ b/account.hh
@@ -2,8 +2,13 @@
 // License, version 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef _ACCOUNT_H_
-#define _ACCOUNT_H_
+#pragma once
+
+#ifdef __cplusplus
+#include <ctime>
+#include <cstdint>
+#include <strophe.h>
+#endif
 
 extern struct t_account *accounts;
 extern struct t_account *last_account;
@@ -129,9 +134,12 @@ extern char *account_options[][2];
 struct t_account *account__search(const char *account_name);
 struct t_account *account__casesearch (const char *account_name);
 int account__search_option(const char *option_name);
-struct t_account_device *account__search_device(struct t_account *account, uint32_t id);
-void account__add_device(struct t_account *account, struct t_account_device *device);
-void account__free_device(struct t_account *account, struct t_account_device *device);
+struct t_account_device *account__search_device(struct t_account *account,
+                                                uint32_t id);
+void account__add_device(struct t_account *account,
+                         struct t_account_device *device);
+void account__free_device(struct t_account *account,
+                          struct t_account_device *device);
 void account__free_device_all(struct t_account *account);
 xmpp_stanza_t *account__get_devicelist(struct t_account *account);
 struct t_account_mam_query *account__add_mam_query(struct t_account *account,
@@ -152,5 +160,3 @@ void account__disconnect_all();
 void account__close_connection(struct t_account *account);
 int account__connect(struct t_account *account);
 int account__timer_cb(const void *pointer, void *data, int remaining_calls);
-
-#endif /*ACCOUNT_H*/
diff --git a/buffer.c b/buffer.c
index d9db4e3..3782ed8 100644
--- a/buffer.c
+++ b/buffer.c
@@ -8,8 +8,8 @@
 #include <weechat/weechat-plugin.h>
 
 #include "plugin.hh"
-#include "account.h"
-#include "channel.h"
+#include "account.hh"
+#include "channel.hh"
 #include "buffer.h"
 
 void buffer__get_account_and_channel(struct t_gui_buffer *buffer,
diff --git a/channel.c b/channel.cpp
similarity index 98%
rename from channel.c
rename to channel.cpp
index 8a7ed86..5194157 100644
--- a/channel.c
+++ b/channel.cpp
@@ -11,10 +11,10 @@
 #include <weechat/weechat-plugin.h>
 
 #include "plugin.hh"
-#include "account.h"
+#include "account.hh"
 #include "omemo.h"
-#include "user.h"
-#include "channel.h"
+#include "user.hh"
+#include "channel.hh"
 #include "input.h"
 #include "buffer.h"
 #include "pgp.h"
@@ -116,7 +116,7 @@ struct t_gui_buffer *channel__search_buffer(struct t_account *account,
     const char *ptr_type, *ptr_account_name, *ptr_remote_jid;
 
     hdata_buffer = weechat_hdata_get("buffer");
-    ptr_buffer = weechat_hdata_get_list(hdata_buffer, "gui_buffers");
+    ptr_buffer = (struct t_gui_buffer*)weechat_hdata_get_list(hdata_buffer, "gui_buffers");
 
     while (ptr_buffer)
     {
@@ -140,7 +140,7 @@ struct t_gui_buffer *channel__search_buffer(struct t_account *account,
                 return ptr_buffer;
             }
         }
-        ptr_buffer = weechat_hdata_move(hdata_buffer, ptr_buffer, 1);
+        ptr_buffer = (struct t_gui_buffer*)weechat_hdata_move(hdata_buffer, ptr_buffer, 1);
     }
 
     return NULL;
@@ -178,7 +178,7 @@ struct t_gui_buffer *channel__create_buffer(struct t_account *account,
 
     if (buffer_created)
     {
-        char *res = strrchr(name, '/');
+        char *res = (char*)strrchr(name, '/');
         if (!weechat_buffer_get_integer(ptr_buffer, "short_name_is_set"))
             weechat_buffer_set(ptr_buffer, "short_name",
                                res ? res + 1 : name);
@@ -221,7 +221,7 @@ struct t_gui_buffer *channel__create_buffer(struct t_account *account,
             weechat_buffer_set(ptr_buffer, "nicklist", "1");
             weechat_buffer_set(ptr_buffer, "nicklist_display_groups", "0");
             weechat_buffer_set_pointer(ptr_buffer, "nicklist_callback",
-                                       &buffer__nickcmp_cb);
+                                       (void*)&buffer__nickcmp_cb);
             weechat_buffer_set_pointer(ptr_buffer, "nicklist_callback_pointer",
                                        account);
         }
@@ -293,7 +293,7 @@ struct t_channel *channel__new(struct t_account *account,
     if (!ptr_buffer)
         return NULL;
 
-    if ((new_channel = malloc(sizeof(*new_channel))) == NULL)
+    if ((new_channel = (struct t_channel*)malloc(sizeof(*new_channel))) == NULL)
         return NULL;
 
     typing_timer = weechat_hook_timer(1 * 1000, 0, 0,
@@ -569,7 +569,7 @@ int channel__add_typing(struct t_channel *channel,
     new_typing = channel__typing_search(channel, user->id);
     if (!new_typing)
     {
-        new_typing = malloc(sizeof(*new_typing));
+        new_typing = (struct t_channel_typing*)malloc(sizeof(*new_typing));
         new_typing->id = strdup(user->id);
         new_typing->name = strdup(user->profile.display_name);
 
@@ -695,7 +695,7 @@ int channel__add_self_typing(struct t_channel *channel,
     new_typing = channel__self_typing_search(channel, user);
     if (!new_typing)
     {
-        new_typing = malloc(sizeof(*new_typing));
+        new_typing = (struct t_channel_typing*)malloc(sizeof(*new_typing));
         new_typing->user = user;
         new_typing->name = user ? strdup(user->profile.display_name) : NULL;
 
@@ -739,7 +739,7 @@ void channel__unread_free_all(struct t_channel *channel)
             struct t_weelist_item *ptr_item = weechat_list_get(channel->unreads, i);
             if (ptr_item)
             {
-                struct t_channel_unread *unread = weechat_list_user_data(ptr_item);
+                struct t_channel_unread *unread = (struct t_channel_unread *)weechat_list_user_data(ptr_item);
 
                 channel__unread_free(unread);
 
@@ -896,7 +896,7 @@ struct t_channel_member *channel__add_member(struct t_account *account,
 
     if (!(member = channel__member_search(channel, id)))
     {
-        member = malloc(sizeof(struct t_channel_member));
+        member = (struct t_channel_member*)malloc(sizeof(struct t_channel_member));
         member->id = strdup(id);
 
         member->role = NULL;
@@ -1114,7 +1114,7 @@ int channel__send_message(struct t_account *account, struct t_channel *channel,
         channel__set_transport(channel, CHANNEL_TRANSPORT_PLAIN, 0);
     }
 
-    char *url = strstr(body, "http");
+    char *url = (char*)strstr(body, "http");
     if (url && channel->transport == CHANNEL_TRANSPORT_PLAIN)
     {
         xmpp_stanza_t *message__x = xmpp_stanza_new(account->context);
@@ -1184,7 +1184,7 @@ void channel__send_reads(struct t_account *account, struct t_channel *channel)
             if (ptr_item)
             {
                 const char *unread_id = weechat_list_string(ptr_item);
-                struct t_channel_unread *unread = weechat_list_user_data(ptr_item);
+                struct t_channel_unread *unread = (struct t_channel_unread*)weechat_list_user_data(ptr_item);
 
                 xmpp_stanza_t *message = xmpp_message_new(account->context, NULL,
                                                           channel->id, NULL);
diff --git a/channel.h b/channel.hh
similarity index 98%
rename from channel.h
rename to channel.hh
index 5643679..da5b556 100644
--- a/channel.h
+++ b/channel.hh
@@ -2,8 +2,11 @@
 // License, version 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef _WEECHAT_XMPP_CHANNEL_H_
-#define _WEECHAT_XMPP_CHANNEL_H_
+#pragma once
+
+#ifdef __cplusplus
+#include <ctime>
+#endif
 
 #define CHANNEL_MEMBERS_SPEAKING_LIMIT 128
 
@@ -208,5 +211,3 @@ void channel__send_paused(struct t_account *account, struct t_channel *channel,
 
 void channel__fetch_mam(struct t_account *account, struct t_channel *channel,
                         const char *id, time_t *start, time_t *end, const char *after);
-
-#endif /*WEECHAT_XMPP_CHANNEL_H*/
diff --git a/command.c b/command.c
index 147239c..6a3ef96 100644
--- a/command.c
+++ b/command.c
@@ -11,9 +11,9 @@
 #include <weechat/weechat-plugin.h>
 
 #include "plugin.hh"
-#include "account.h"
-#include "user.h"
-#include "channel.h"
+#include "account.hh"
+#include "user.hh"
+#include "channel.hh"
 #include "buffer.h"
 #include "message.h"
 #include "command.h"
diff --git a/completion.c b/completion.c
index 3bf9da7..b386e0d 100644
--- a/completion.c
+++ b/completion.c
@@ -11,9 +11,9 @@
 
 #include "plugin.hh"
 #include "config.hh"
-#include "account.h"
-#include "channel.h"
-#include "user.h"
+#include "account.hh"
+#include "channel.hh"
+#include "user.hh"
 #include "buffer.h"
 #include "completion.h"
 
diff --git a/config.cpp b/config.cpp
index 4c538f2..3944b3d 100644
--- a/config.cpp
+++ b/config.cpp
@@ -9,7 +9,7 @@
 #include <weechat/weechat-plugin.h>
 
 #include "plugin.hh"
-#include "account.h"
+#include "account.hh"
 #include "config.hh"
 
 struct t_config_file *config_file;
diff --git a/connection.c b/connection.c
index 643fac7..37be767 100644
--- a/connection.c
+++ b/connection.c
@@ -14,9 +14,9 @@
 #include "plugin.hh"
 #include "xmpp/stanza.hh"
 #include "config.hh"
-#include "account.h"
-#include "user.h"
-#include "channel.h"
+#include "account.hh"
+#include "user.hh"
+#include "channel.hh"
 #include "connection.h"
 #include "omemo.h"
 #include "pgp.h"
diff --git a/input.c b/input.c
index 816ec84..215dad9 100644
--- a/input.c
+++ b/input.c
@@ -8,8 +8,8 @@
 #include <weechat/weechat-plugin.h>
 
 #include "plugin.hh"
-#include "account.h"
-#include "channel.h"
+#include "account.hh"
+#include "channel.hh"
 #include "buffer.h"
 #include "message.h"
 #include "input.h"
diff --git a/makefile b/makefile
index b601f45..f43f75a 100644
--- a/makefile
+++ b/makefile
@@ -40,9 +40,9 @@ PREFIX ?= /usr/local
 LIBDIR ?= $(PREFIX)/lib
 
 HDRS=plugin.hh \
-     account.h \
+     account.hh \
      buffer.h \
-     channel.h \
+     channel.hh \
      command.h \
      completion.h \
      config.hh \
@@ -51,14 +51,14 @@ HDRS=plugin.hh \
      message.h \
      omemo.h \
      pgp.h \
-     user.h \
+     user.hh \
      util.h \
      xmpp/stanza.hh \
 
 SRCS=plugin.cpp \
-	 account.c \
+	 account.cpp \
 	 buffer.c \
-	 channel.c \
+	 channel.cpp \
 	 command.c \
 	 completion.c \
 	 config.cpp \
@@ -67,7 +67,7 @@ SRCS=plugin.cpp \
 	 message.c \
 	 omemo.c \
 	 pgp.c \
-	 user.c \
+	 user.cpp \
 	 util.c \
 	 xmpp/presence.cpp \
 	 xmpp/iq.cpp \
diff --git a/message.c b/message.c
index 2d9c2ce..49deb8a 100644
--- a/message.c
+++ b/message.c
@@ -11,9 +11,9 @@
 #include <weechat/weechat-plugin.h>
 
 #include "plugin.hh"
-#include "account.h"
-#include "channel.h"
-#include "user.h"
+#include "account.hh"
+#include "channel.hh"
+#include "user.hh"
 #include "message.h"
 
 static const char format_regex[] = "<([^>]*?)>";
diff --git a/omemo.c b/omemo.c
index 4709412..d38040c 100644
--- a/omemo.c
+++ b/omemo.c
@@ -32,7 +32,7 @@ struct t_pre_key {
 
 #include "plugin.hh"
 #include "xmpp/stanza.hh"
-#include "account.h"
+#include "account.hh"
 #include "omemo.h"
 #include "util.h"
 
diff --git a/plugin.cpp b/plugin.cpp
index 6490a85..7f3be51 100644
--- a/plugin.cpp
+++ b/plugin.cpp
@@ -12,7 +12,7 @@
 #include "plugin.hh"
 #include "config.hh"
 extern "C" {
-#include "account.h"
+#include "account.hh"
 #include "connection.h"
 #include "command.h"
 #include "input.h"
diff --git a/tests/run b/tests/run
index f158e82..21b73ce 100755
Binary files a/tests/run and b/tests/run differ
diff --git a/user.c b/user.cpp
similarity index 98%
rename from user.c
rename to user.cpp
index 78fe334..4cf5c7b 100644
--- a/user.c
+++ b/user.cpp
@@ -10,9 +10,9 @@
 #include <weechat/weechat-plugin.h>
 
 #include "plugin.hh"
-#include "account.h"
-#include "user.h"
-#include "channel.h"
+#include "account.hh"
+#include "user.hh"
+#include "channel.hh"
 
 const char *user__get_colour(struct t_user *user)
 {
@@ -166,7 +166,7 @@ struct t_user *user__new(struct t_account *account,
         return ptr_user;
     }
 
-    if ((new_user = malloc(sizeof(*new_user))) == NULL)
+    if ((new_user = (struct t_user*)malloc(sizeof(*new_user))) == NULL)
     {
         return NULL;
     }
diff --git a/user.h b/user.hh
similarity index 94%
rename from user.h
rename to user.hh
index ccc9537..02afaee 100644
--- a/user.h
+++ b/user.hh
@@ -2,8 +2,7 @@
 // License, version 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef _WEECHAT_XMPP_USER_H_
-#define _WEECHAT_XMPP_USER_H_
+#pragma once
 
 struct t_user_profile
 {
@@ -31,6 +30,7 @@ struct t_user
     struct t_user *prev_user;
     struct t_user *next_user;
 };
+
 struct t_channel;
 
 const char *user__get_colour(struct t_user *user);
@@ -57,5 +57,3 @@ void user__nicklist_add(struct t_account *account,
 void user__nicklist_remove(struct t_account *account,
                            struct t_channel *channel,
                            struct t_user *user);
-
-#endif /*WEECHAT_XMPP_USER_H*/