diff --git a/android/src/main/java/com/RNFetchBlob/RNFetchBlobBody.java b/android/src/main/java/com/RNFetchBlob/RNFetchBlobBody.java
index df4e9088e..3150eb2e8 100644
--- a/android/src/main/java/com/RNFetchBlob/RNFetchBlobBody.java
+++ b/android/src/main/java/com/RNFetchBlob/RNFetchBlobBody.java
@@ -281,7 +281,7 @@ private File createMultipartBodyCache() throws IOException {
      */
     private void pipeStreamToSink(InputStream stream, BufferedSink sink) throws IOException {
         byte[] chunk = new byte[10240];
-        int totalWritten = 0;
+        long totalWritten = 0;
         int read;
         while((read = stream.read(chunk, 0, 10240)) > 0) {
             sink.write(chunk, 0, read);
@@ -403,7 +403,7 @@ private class FormField {
      * Emit progress event
      * @param written  Integer
      */
-    private void emitUploadProgress(int written) {
+    private void emitUploadProgress(long written) {
         RNFetchBlobProgressConfig config = RNFetchBlobReq.getReportUploadProgress(mTaskId);
         if(config != null && contentLength != 0 && config.shouldReport((float)written/contentLength)) {
             WritableMap args = Arguments.createMap();
diff --git a/ios/RNFetchBlobRequest.m b/ios/RNFetchBlobRequest.m
index c77668ce8..a56cc92d0 100644
--- a/ios/RNFetchBlobRequest.m
+++ b/ios/RNFetchBlobRequest.m
@@ -345,8 +345,8 @@ - (void) URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dat
          sendDeviceEventWithName:EVENT_PROGRESS
          body:@{
                 @"taskId": taskId,
-                @"written": [NSString stringWithFormat:@"%ld", (long) receivedBytes],
-                @"total": [NSString stringWithFormat:@"%ld", (long) expectedBytes],
+                @"written": [NSString stringWithFormat:@"%lld", (long long) receivedBytes],
+                @"total": [NSString stringWithFormat:@"%lld", (long long) expectedBytes],
                 @"chunk": chunkString
                 }
          ];