diff --git a/jsonmessage/jsonmessage.go b/jsonmessage/jsonmessage.go
index 7db1626..0c93ee6 100644
--- a/jsonmessage/jsonmessage.go
+++ b/jsonmessage/jsonmessage.go
@@ -23,8 +23,8 @@ func (e *JSONError) Error() string {
 
 type JSONProgress struct {
 	terminalFd uintptr
-	Current    int   `json:"current,omitempty"`
-	Total      int   `json:"total,omitempty"`
+	Current    int64 `json:"current,omitempty"`
+	Total      int64 `json:"total,omitempty"`
 	Start      int64 `json:"start,omitempty"`
 }
 
@@ -64,7 +64,7 @@ func (p *JSONProgress) String() string {
 	numbersBox = fmt.Sprintf("%8v/%v", current, total)
 
 	if p.Current > 0 && p.Start > 0 && percentage < 50 {
-		fromStart := time.Now().UTC().Sub(time.Unix(int64(p.Start), 0))
+		fromStart := time.Now().UTC().Sub(time.Unix(p.Start, 0))
 		perEntry := fromStart / time.Duration(p.Current)
 		left := time.Duration(p.Total-p.Current) * perEntry
 		left = (left / time.Second) * time.Second
diff --git a/progressreader/progressreader.go b/progressreader/progressreader.go
index d55fadd..f48442b 100644
--- a/progressreader/progressreader.go
+++ b/progressreader/progressreader.go
@@ -14,9 +14,9 @@ type Config struct {
 	In         io.ReadCloser // Stream to read from
 	Out        io.Writer     // Where to send progress bar to
 	Formatter  *streamformatter.StreamFormatter
-	Size       int
-	Current    int
-	LastUpdate int
+	Size       int64
+	Current    int64
+	LastUpdate int64
 	NewLines   bool
 	ID         string
 	Action     string
@@ -29,11 +29,11 @@ func New(newReader Config) *Config {
 
 func (config *Config) Read(p []byte) (n int, err error) {
 	read, err := config.In.Read(p)
-	config.Current += read
-	updateEvery := 1024 * 512 //512kB
+	config.Current += int64(read)
+	updateEvery := int64(1024 * 512) //512kB
 	if config.Size > 0 {
 		// Update progress for every 1% read if 1% < 512kB
-		if increment := int(0.01 * float64(config.Size)); increment < updateEvery {
+		if increment := int64(0.01 * float64(config.Size)); increment < updateEvery {
 			updateEvery = increment
 		}
 	}
diff --git a/progressreader/progressreader_test.go b/progressreader/progressreader_test.go
index fdf40cb..21d9b0f 100644
--- a/progressreader/progressreader_test.go
+++ b/progressreader/progressreader_test.go
@@ -20,7 +20,7 @@ func TestOutputOnPrematureClose(t *testing.T) {
 		In:        reader,
 		Out:       writer,
 		Formatter: streamformatter.NewStreamFormatter(),
-		Size:      len(content),
+		Size:      int64(len(content)),
 		NewLines:  true,
 		ID:        "Test",
 		Action:    "Read",
@@ -60,7 +60,7 @@ func TestCompleteSilently(t *testing.T) {
 		In:        reader,
 		Out:       writer,
 		Formatter: streamformatter.NewStreamFormatter(),
-		Size:      len(content),
+		Size:      int64(len(content)),
 		NewLines:  true,
 		ID:        "Test",
 		Action:    "Read",
diff --git a/tarsum/versioning.go b/tarsum/versioning.go
index 8988b9f..2882286 100644
--- a/tarsum/versioning.go
+++ b/tarsum/versioning.go
@@ -95,17 +95,17 @@ func (f tarHeaderSelectFunc) selectHeaders(h *tar.Header) (orderedHeaders [][2]s
 func v0TarHeaderSelect(h *tar.Header) (orderedHeaders [][2]string) {
 	return [][2]string{
 		{"name", h.Name},
-		{"mode", strconv.Itoa(int(h.Mode))},
+		{"mode", strconv.FormatInt(h.Mode, 10)},
 		{"uid", strconv.Itoa(h.Uid)},
 		{"gid", strconv.Itoa(h.Gid)},
-		{"size", strconv.Itoa(int(h.Size))},
-		{"mtime", strconv.Itoa(int(h.ModTime.UTC().Unix()))},
+		{"size", strconv.FormatInt(h.Size, 10)},
+		{"mtime", strconv.FormatInt(h.ModTime.UTC().Unix(), 10)},
 		{"typeflag", string([]byte{h.Typeflag})},
 		{"linkname", h.Linkname},
 		{"uname", h.Uname},
 		{"gname", h.Gname},
-		{"devmajor", strconv.Itoa(int(h.Devmajor))},
-		{"devminor", strconv.Itoa(int(h.Devminor))},
+		{"devmajor", strconv.FormatInt(h.Devmajor, 10)},
+		{"devminor", strconv.FormatInt(h.Devminor, 10)},
 	}
 }