diff --git a/CMakeLists.txt b/CMakeLists.txt
index b1e9334..e8e1daa 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,6 @@
 cmake_minimum_required (VERSION 3.7)
 project (mastodon-cpp
-         VERSION 0.7.14
+         VERSION 0.7.15
          LANGUAGES CXX
 )
 
diff --git a/src/easy/account.cpp b/src/easy/account.cpp
index bf9b44a..92cde18 100644
--- a/src/easy/account.cpp
+++ b/src/easy/account.cpp
@@ -53,12 +53,12 @@ const string Account::display_name() const
     return get_string("display_name");
 }
 
-const std::uint64_t Account::followers_count() const
+const std::uint_fast64_t Account::followers_count() const
 {
     return get_uint64("followers_count");
 }
 
-const std::uint64_t Account::following_count() const
+const std::uint_fast64_t Account::following_count() const
 {
     return get_uint64("following_count");
 }
@@ -73,7 +73,7 @@ const string Account::header_static() const
     return get_string("header_static");
 }
 
-const std::uint64_t Account::id() const
+const std::uint_fast64_t Account::id() const
 {
     return std::stoull(get_string("id"));
 }
@@ -135,7 +135,7 @@ const bool Account::sensitive() const
     return get_bool("source.sensitive");
 }
 
-const std::uint64_t Account::statuses_count() const
+const std::uint_fast64_t Account::statuses_count() const
 {
     return get_uint64("statuses_count");
 }
diff --git a/src/easy/account.hpp b/src/easy/account.hpp
index 9727786..30559bc 100644
--- a/src/easy/account.hpp
+++ b/src/easy/account.hpp
@@ -31,7 +31,7 @@
 #endif
 
 using std::string;
-using std::uint64_t;
+using std::uint_fast64_t;
 using std::chrono::system_clock;
 
 namespace Mastodon
@@ -85,12 +85,12 @@ namespace Mastodon
         /*!
          *  @brief  Returns number of followers
          */
-        const uint64_t followers_count() const;
+        const uint_fast64_t followers_count() const;
 
         /*!
          *  @brief  Returns number of people this account follows
          */
-        const uint64_t following_count() const;
+        const uint_fast64_t following_count() const;
 
         /*!
          *  @brief  Returns URL of header image
@@ -105,7 +105,7 @@ namespace Mastodon
         /*!
          *  @brief  Returns account-ID
          */
-        const uint64_t id() const;
+        const uint_fast64_t id() const;
 
         /*!
          *  @brief  Returns true if the account is locked
@@ -146,7 +146,7 @@ namespace Mastodon
         /*!
          *  @brief  Returns number of statuses
          */
-        const uint64_t statuses_count() const;
+        const uint_fast64_t statuses_count() const;
 
         /*!
          *  @brief  Returns URL of the profile
diff --git a/src/easy/attachment.cpp b/src/easy/attachment.cpp
index e89a43d..461d527 100644
--- a/src/easy/attachment.cpp
+++ b/src/easy/attachment.cpp
@@ -44,7 +44,7 @@ const string Attachment::description() const
     return get_string("description");
 }
 
-const std::array<uint64_t, 2> Attachment::focus() const
+const std::array<uint_fast64_t, 2> Attachment::focus() const
 {
     const Json::Value x = get("meta.focus.x");
     const Json::Value y = get("meta.focus.y");
@@ -60,17 +60,17 @@ const std::array<uint64_t, 2> Attachment::focus() const
     return {};
 }
 
-const uint64_t Attachment::height() const
+const uint_fast64_t Attachment::height() const
 {
     return get_uint64("meta.original.height");
 }
 
-const uint64_t Attachment::height_small() const
+const uint_fast64_t Attachment::height_small() const
 {
     return get_uint64("meta.small.height");
 }
 
-const std::uint64_t Attachment::id() const
+const std::uint_fast64_t Attachment::id() const
 {
     return std::stoull(get_string("id"));
 }
@@ -121,12 +121,12 @@ const string Attachment::url() const
     return get_string("url");
 }
 
-const uint64_t Attachment::width() const
+const uint_fast64_t Attachment::width() const
 {
     return get_uint64("meta.original.width");
 }
 
-const uint64_t Attachment::width_small() const
+const uint_fast64_t Attachment::width_small() const
 {
     return get_uint64("meta.small.width");
 }
diff --git a/src/easy/attachment.hpp b/src/easy/attachment.hpp
index 3f39d1f..a6b4524 100644
--- a/src/easy/attachment.hpp
+++ b/src/easy/attachment.hpp
@@ -33,7 +33,7 @@
 
 using std::string;
 using std::uint16_t;
-using std::uint64_t;
+using std::uint_fast64_t;
 
 namespace Mastodon
 {
@@ -74,22 +74,22 @@ namespace Mastodon
          *  @brief  Returns the focus point (x, y)
          */
         // TODO: find attachment with focus
-        const std::array<uint64_t, 2> focus() const;
+        const std::array<uint_fast64_t, 2> focus() const;
 
         /*!
          *  @brief  Returns the height of the original image
          */
-        const uint64_t height() const;
+        const uint_fast64_t height() const;
 
         /*!
          *  @brief  Returns the height of the preview image
          */
-        const uint64_t height_small() const;
+        const uint_fast64_t height_small() const;
 
         /*!
          *  @brief  Returns the ID of the attachment
          */
-        const uint64_t id() const;
+        const uint_fast64_t id() const;
 
         /*!
          *  @brief  Returns the URL of the preview image
@@ -129,18 +129,18 @@ namespace Mastodon
         /*!
          *  @brief  Returns the width of the original image
          */
-        const uint64_t width() const;
+        const uint_fast64_t width() const;
 
         /*!
          *  @brief  Returns the width of the preview image
          */
-        const uint64_t width_small() const;
+        const uint_fast64_t width_small() const;
 
 
         // TODO: find an attachment with framerate, duration or bitrate set
         // const uint16_t framerate() const;
         // const std::chrono::seconds duration() const;
-        // const uint64_t bitrate() const;
+        // const uint_fast64_t bitrate() const;
     };
 }
 
diff --git a/src/easy/card.cpp b/src/easy/card.cpp
index 86f0df4..306baaa 100644
--- a/src/easy/card.cpp
+++ b/src/easy/card.cpp
@@ -43,7 +43,7 @@ const string Card::description() const
     return get_string("description");
 }
 
-const uint64_t Card::height() const
+const uint_fast64_t Card::height() const
 {
     return get_uint64("height");
 }
@@ -94,7 +94,7 @@ const string Card::url() const
     return get_string("url");
 }
 
-const uint64_t Card::width() const
+const uint_fast64_t Card::width() const
 {
     return get_uint64("width");
 }
diff --git a/src/easy/card.hpp b/src/easy/card.hpp
index 40bf49c..5b5036e 100644
--- a/src/easy/card.hpp
+++ b/src/easy/card.hpp
@@ -30,7 +30,7 @@
 #endif
 
 using std::string;
-using std::uint64_t;
+using std::uint_fast64_t;
 
 namespace Mastodon
 {
@@ -70,7 +70,7 @@ namespace Mastodon
         /*!
          *  @brief  Returns the height of the card
          */
-        const uint64_t height() const;
+        const uint_fast64_t height() const;
 
         /*!
          *  @brief  Returns the HTML
@@ -110,7 +110,7 @@ namespace Mastodon
         /*!
          *  @brief  Returns the width of the card
          */
-        const uint64_t width() const;
+        const uint_fast64_t width() const;
     };
 }
 
diff --git a/src/easy/easy.cpp b/src/easy/easy.cpp
index 477d25e..43d4668 100644
--- a/src/easy/easy.cpp
+++ b/src/easy/easy.cpp
@@ -22,7 +22,7 @@
 
 using namespace Mastodon;
 using std::string;
-using std::uint64_t;
+using std::uint_fast64_t;
 using std::chrono::system_clock;
 
 Easy::Easy(const string &instance, const string &access_token)
@@ -124,7 +124,7 @@ const string Easy::Entity::get_string(const string &key) const
     return "";
 }
 
-const uint64_t Easy::Entity::get_uint64(const string &key) const
+const uint_fast64_t Easy::Entity::get_uint64(const string &key) const
 {
     const Json::Value node = get(key);
 
diff --git a/src/easy/easy.hpp b/src/easy/easy.hpp
index b3d0cf6..e57cd14 100644
--- a/src/easy/easy.hpp
+++ b/src/easy/easy.hpp
@@ -31,7 +31,7 @@
 #endif
 
 using std::string;
-using std::uint64_t;
+using std::uint_fast64_t;
 using std::chrono::system_clock;
 
 namespace Mastodon
@@ -147,11 +147,11 @@ public:
         const string get_string(const string &key) const;
 
         /*!
-         *  @brief  Returns the value of key as std::uint64_t
+         *  @brief  Returns the value of key as std::uint_fast64_t
          *  
          *          Returns 0 on error.
          */
-        const uint64_t get_uint64(const string &key) const;
+        const uint_fast64_t get_uint64(const string &key) const;
 
         /*!
          *  @brief  Returns the value of key as double
diff --git a/src/easy/list.cpp b/src/easy/list.cpp
index a148a35..9b0e413 100644
--- a/src/easy/list.cpp
+++ b/src/easy/list.cpp
@@ -19,7 +19,7 @@
 using namespace Mastodon;
 using List = Easy::List;
 using std::string;
-using std::uint64_t;
+using std::uint_fast64_t;
 
 List::List(const string &json)
 : Entity(json)
@@ -29,7 +29,7 @@ List::List()
 : Entity()
 {}
 
-const uint64_t List::id() const
+const uint_fast64_t List::id() const
 {
     return std::stoull(get_string("id"));
 }
diff --git a/src/easy/list.hpp b/src/easy/list.hpp
index 2e8a5e3..654cbda 100644
--- a/src/easy/list.hpp
+++ b/src/easy/list.hpp
@@ -31,7 +31,7 @@
 #endif
 
 using std::string;
-using std::uint64_t;
+using std::uint_fast64_t;
 
 namespace Mastodon
 {
@@ -56,7 +56,7 @@ namespace Mastodon
         /*!
          *  @brief  Returns list-ID
          */
-        const uint64_t id() const;
+        const uint_fast64_t id() const;
 
         /*!
          *  @brief  Returns title
diff --git a/src/easy/mention.cpp b/src/easy/mention.cpp
index fe8be65..ba90b58 100644
--- a/src/easy/mention.cpp
+++ b/src/easy/mention.cpp
@@ -32,7 +32,7 @@ const string Mention::acct() const
     return get_string("acct");
 }
 
-const uint64_t Mention::id() const
+const uint_fast64_t Mention::id() const
 {
     return std::stoull(get_string("id"));
 }
diff --git a/src/easy/mention.hpp b/src/easy/mention.hpp
index 95cd7dc..9865b16 100644
--- a/src/easy/mention.hpp
+++ b/src/easy/mention.hpp
@@ -30,7 +30,7 @@
 #endif
 
 using std::string;
-using std::uint64_t;
+using std::uint_fast64_t;
 using std::chrono::system_clock;
 
 namespace Mastodon
@@ -61,7 +61,7 @@ namespace Mastodon
         /*!
          *  @brief  Returns account ID
          */
-        const uint64_t id() const;
+        const uint_fast64_t id() const;
 
         /*!
          *  @brief  Returns the URL of user's profile
diff --git a/src/easy/notification.cpp b/src/easy/notification.cpp
index 856ad87..af5234b 100644
--- a/src/easy/notification.cpp
+++ b/src/easy/notification.cpp
@@ -45,7 +45,7 @@ const system_clock::time_point Notification::created_at() const
     return get_time_point("created_at");
 }
 
-const uint64_t Notification::id() const
+const uint_fast64_t Notification::id() const
 {
     return std::stoull(get_string("id"));
 }
diff --git a/src/easy/notification.hpp b/src/easy/notification.hpp
index ab5ff44..c9db8b7 100644
--- a/src/easy/notification.hpp
+++ b/src/easy/notification.hpp
@@ -35,7 +35,7 @@
 #endif
 
 using std::string;
-using std::uint64_t;
+using std::uint_fast64_t;
 using std::chrono::system_clock;
 
 namespace Mastodon
@@ -71,7 +71,7 @@ namespace Mastodon
         /*!
          *  @brief  Returns notification ID
          */
-        const uint64_t id() const;
+        const uint_fast64_t id() const;
 
         /*!
          *  @brief  Returns the Status associated with the notification, if
diff --git a/src/easy/relationship.cpp b/src/easy/relationship.cpp
index a80a5a4..45a7b9a 100644
--- a/src/easy/relationship.cpp
+++ b/src/easy/relationship.cpp
@@ -47,7 +47,7 @@ const bool Relationship::following() const
     return get_bool("following");
 }
 
-const uint64_t Relationship::id() const
+const uint_fast64_t Relationship::id() const
 {
     return std::stoull(get_string("id"));
 }
diff --git a/src/easy/relationship.hpp b/src/easy/relationship.hpp
index cb68afc..72402c7 100644
--- a/src/easy/relationship.hpp
+++ b/src/easy/relationship.hpp
@@ -30,7 +30,7 @@
 #endif
 
 using std::string;
-using std::uint64_t;
+using std::uint_fast64_t;
 
 namespace Mastodon
 {
@@ -75,7 +75,7 @@ namespace Mastodon
         /*!
          *  @brief  Returns the target account ID
          */
-        const uint64_t id() const;
+        const uint_fast64_t id() const;
 
         /*!
          *  @brief  Returns true if the user is muting the account
diff --git a/src/easy/report.cpp b/src/easy/report.cpp
index 84f0e3d..3fe79fe 100644
--- a/src/easy/report.cpp
+++ b/src/easy/report.cpp
@@ -32,7 +32,7 @@ const bool Report::action_taken() const
     return get_bool("action_taken");
 }
 
-const uint64_t Report::id() const
+const uint_fast64_t Report::id() const
 {
     return std::stoull(get_string("id"));
 }
diff --git a/src/easy/report.hpp b/src/easy/report.hpp
index c18a596..93905cb 100644
--- a/src/easy/report.hpp
+++ b/src/easy/report.hpp
@@ -30,7 +30,7 @@
 #endif
 
 using std::string;
-using std::uint64_t;
+using std::uint_fast64_t;
 
 namespace Mastodon
 {
@@ -61,7 +61,7 @@ namespace Mastodon
         /*!
          *  @brief  Returns the ID of the report
          */
-        const uint64_t id() const;
+        const uint_fast64_t id() const;
     };
 }
 
diff --git a/src/easy/status.cpp b/src/easy/status.cpp
index 58e62fb..4e723bf 100644
--- a/src/easy/status.cpp
+++ b/src/easy/status.cpp
@@ -85,22 +85,22 @@ const bool Status::favourited() const
     return get_bool("favourited");
 }
 
-const uint64_t Status::favourites_count() const
+const uint_fast64_t Status::favourites_count() const
 {
     return get_uint64("favourites_count");
 }
 
-const uint64_t Status::id() const
+const uint_fast64_t Status::id() const
 {
     return get_uint64("id");
 }
 
-const uint64_t Status::in_reply_to_id() const
+const uint_fast64_t Status::in_reply_to_id() const
 {
     return get_uint64("in_reply_to_id");
 }
 
-const uint64_t Status::in_reply_to_account_id() const
+const uint_fast64_t Status::in_reply_to_account_id() const
 {
     return get_uint64("in_reply_to_account_id");
 }
@@ -171,7 +171,7 @@ const bool Status::reblogged() const
     return get_bool("reblogged");
 }
 
-const uint64_t Status::reblogs_count() const
+const uint_fast64_t Status::reblogs_count() const
 {
     return get_uint64("reblogs_count");
 }
diff --git a/src/easy/status.hpp b/src/easy/status.hpp
index 26b5ecb..e842a86 100644
--- a/src/easy/status.hpp
+++ b/src/easy/status.hpp
@@ -44,7 +44,7 @@
 #endif
 
 using std::string;
-using std::uint64_t;
+using std::uint_fast64_t;
 using std::chrono::system_clock;
 
 namespace Mastodon
@@ -100,22 +100,22 @@ namespace Mastodon
         /*!
          *  @brief  Returns the number of favourites
          */
-        const uint64_t favourites_count() const;
+        const uint_fast64_t favourites_count() const;
 
         /*!
          *  @brief  Returns the ID of the status
          */
-        const uint64_t id() const;
+        const uint_fast64_t id() const;
 
         /*!
          *  @brief  Returns the ID of the status it replies to
          */
-        const uint64_t in_reply_to_id() const;
+        const uint_fast64_t in_reply_to_id() const;
 
         /*!
          *  @brief  Returns the ID of the account it replies to
          */
-        const uint64_t in_reply_to_account_id() const;
+        const uint_fast64_t in_reply_to_account_id() const;
 
         /*!
          *  @brief  Returns the language of the status
@@ -155,7 +155,7 @@ namespace Mastodon
         /*!
          *  @brief  Returns the number of reblogs for the status
          */
-        const uint64_t reblogs_count() const;
+        const uint_fast64_t reblogs_count() const;
 
         /*!
          *  @brief  Returns true if the attachments should be hidden by default