diff --git a/src/uvw/fs.hpp b/src/uvw/fs.hpp
index 6028289d..ef2536e2 100644
--- a/src/uvw/fs.hpp
+++ b/src/uvw/fs.hpp
@@ -128,8 +128,8 @@ template<>
 struct FsEvent<details::UVFsType::READ>
         : Event<FsEvent<details::UVFsType::READ>>
 {
-    FsEvent(const char *path, std::unique_ptr<const char[]> data, ssize_t size) noexcept
-        : path{path}, data{std::move(data)}, size(size)
+    FsEvent(const char *path, std::unique_ptr<const char[]> data, std::size_t size) noexcept
+        : path{path}, data{std::move(data)}, size{size}
     { }
 
     const char * path; /*!< The path affecting the request. */
@@ -148,8 +148,8 @@ template<>
 struct FsEvent<details::UVFsType::WRITE>
         : Event<FsEvent<details::UVFsType::WRITE>>
 {
-    FsEvent(const char *path, ssize_t size) noexcept
-        : path{path}, size(size)
+    FsEvent(const char *path, std::size_t size) noexcept
+        : path{path}, size{size}
     { }
 
     const char * path; /*!< The path affecting the request. */
@@ -167,8 +167,8 @@ template<>
 struct FsEvent<details::UVFsType::SENDFILE>
         : Event<FsEvent<details::UVFsType::SENDFILE>>
 {
-    FsEvent(const char *path, ssize_t size) noexcept
-        : path{path}, size(size)
+    FsEvent(const char *path, std::size_t size) noexcept
+        : path{path}, size{size}
     { }
 
     const char * path; /*!< The path affecting the request. */
@@ -243,8 +243,8 @@ template<>
 struct FsEvent<details::UVFsType::SCANDIR>
         : Event<FsEvent<details::UVFsType::SCANDIR>>
 {
-    FsEvent(const char *path, ssize_t size) noexcept
-        : path{path}, size(size)
+    FsEvent(const char *path, std::size_t size) noexcept
+        : path{path}, size{size}
     { }
 
     const char * path; /*!< The path affecting the request. */
@@ -262,8 +262,8 @@ template<>
 struct FsEvent<details::UVFsType::READLINK>
         : Event<FsEvent<details::UVFsType::READLINK>>
 {
-    explicit FsEvent(const char *path, const char *data, ssize_t size) noexcept
-        : path{path}, data{data}, size(size)
+    explicit FsEvent(const char *path, const char *data, std::size_t size) noexcept
+        : path{path}, data{data}, size{size}
     { }
 
     const char * path; /*!< The path affecting the request. */
@@ -291,7 +291,7 @@ protected:
     static void fsResultCallback(uv_fs_t *req) {
         auto ptr = Request<T, uv_fs_t>::reserve(req);
         if(req->result < 0) { ptr->publish(ErrorEvent{req->result}); }
-        else { ptr->publish(FsEvent<e>{req->path, req->result}); }
+        else { ptr->publish(FsEvent<e>{req->path, static_cast<std::size_t>(req->result)}); }
     }
 
     template<details::UVFsType e>
@@ -363,7 +363,7 @@ class FileReq final: public FsRequest<FileReq> {
     static void fsReadCallback(uv_fs_t *req) {
         auto ptr = reserve(req);
         if(req->result < 0) { ptr->publish(ErrorEvent{req->result}); }
-        else { ptr->publish(FsEvent<Type::READ>{req->path, std::move(ptr->data), req->result}); }
+        else { ptr->publish(FsEvent<Type::READ>{req->path, std::move(ptr->data), static_cast<std::size_t>(req->result)}); }
     }
 
 public:
@@ -746,7 +746,7 @@ class FsReq final: public FsRequest<FsReq> {
     static void fsReadlinkCallback(uv_fs_t *req) {
         auto ptr = reserve(req);
         if(req->result < 0) { ptr->publish(ErrorEvent{req->result}); }
-        else { ptr->publish(FsEvent<Type::READLINK>{req->path, static_cast<char *>(req->ptr), req->result}); }
+        else { ptr->publish(FsEvent<Type::READLINK>{req->path, static_cast<char *>(req->ptr), static_cast<std::size_t>(req->result)}); }
     }
 
 public:
diff --git a/src/uvw/stream.hpp b/src/uvw/stream.hpp
index 2bb6d9fd..730b18a4 100644
--- a/src/uvw/stream.hpp
+++ b/src/uvw/stream.hpp
@@ -62,8 +62,8 @@ struct WriteEvent: Event<WriteEvent> { };
  * It will be emitted by StreamHandle according with its functionalities.
  */
 struct DataEvent: Event<DataEvent> {
-    explicit DataEvent(std::unique_ptr<char[]> data, ssize_t length) noexcept
-        : data{std::move(data)}, length(length)
+    explicit DataEvent(std::unique_ptr<char[]> data, std::size_t length) noexcept
+        : data{std::move(data)}, length{length}
     { }
 
     std::unique_ptr<char[]> data; /*!< A bunch of data read on the stream. */
@@ -141,7 +141,7 @@ class StreamHandle: public Handle<T, U> {
             ref.publish(EndEvent{});
         } else if(nread > 0) {
             // data available
-            ref.publish(DataEvent{std::move(data), nread});
+            ref.publish(DataEvent{std::move(data), static_cast<std::size_t>(nread)});
         } else {
             // transmission error
             ref.publish(ErrorEvent(nread));
diff --git a/src/uvw/udp.hpp b/src/uvw/udp.hpp
index 87d3cc4b..874db86a 100644
--- a/src/uvw/udp.hpp
+++ b/src/uvw/udp.hpp
@@ -32,8 +32,8 @@ struct SendEvent: Event<SendEvent> { };
  * It will be emitted by UDPHandle according with its functionalities.
  */
 struct UDPDataEvent: Event<UDPDataEvent> {
-    explicit UDPDataEvent(Addr sender, std::unique_ptr<const char[]> data, ssize_t length, bool partial) noexcept
-        : data{std::move(data)}, length(length), sender{std::move(sender)}, partial{partial}
+    explicit UDPDataEvent(Addr sender, std::unique_ptr<const char[]> data, std::size_t length, bool partial) noexcept
+        : data{std::move(data)}, length{length}, sender{std::move(sender)}, partial{partial}
     { }
 
     std::unique_ptr<const char[]> data; /*!< A bunch of data read on the stream. */