diff --git a/fastboot/usb_linux.c b/fastboot/usb_linux.c
index 78b7b98..1ba87e6 100644
--- a/fastboot/usb_linux.c
+++ b/fastboot/usb_linux.c
@@ -61,6 +61,11 @@
 #define DBG1(x...)
 #endif
 
+/* The max bulk size for linux is 16384 which is defined
+ * in drivers/usb/core/devio.c.
+ */
+#define MAX_USBFS_BULK_SIZE (16 * 1024)
+
 struct usb_handle 
 {
     char fname[64];
@@ -289,7 +294,7 @@
     
     while(len > 0) {
         int xfer;
-        xfer = (len > 4096) ? 4096 : len;
+        xfer = (len > MAX_USBFS_BULK_SIZE) ? MAX_USBFS_BULK_SIZE : len;
         
         bulk.ep = h->ep_out;
         bulk.len = xfer;
@@ -323,7 +328,7 @@
     }
     
     while(len > 0) {
-        int xfer = (len > 4096) ? 4096 : len;
+        int xfer = (len > MAX_USBFS_BULK_SIZE) ? MAX_USBFS_BULK_SIZE : len;
         
         bulk.ep = h->ep_in;
         bulk.len = xfer;
diff --git a/fastboot/usb_windows.c b/fastboot/usb_windows.c
index 54008a4..1050293 100644
--- a/fastboot/usb_windows.c
+++ b/fastboot/usb_windows.c
@@ -42,6 +42,7 @@
 #define DBG(x...)
 #endif
 
+#define MAX_USBFS_BULK_SIZE (1024 * 1024)
 
 /** Structure usb_handle describes our connection to the usb device via
   AdbWinApi.dll. This structure is returned from usb_open() routine and
@@ -160,7 +161,7 @@
     if (NULL != handle) {
         // Perform write
         while(len > 0) {
-            int xfer = (len > 4096) ? 4096 : len;
+            int xfer = (len > MAX_USBFS_BULK_SIZE) ? MAX_USBFS_BULK_SIZE : len;
             ret = AdbWriteEndpointSync(handle->adb_write_pipe,
                                    (void*)data,
                                    (unsigned long)xfer,
@@ -200,7 +201,7 @@
     DBG("usb_read %d\n", len);
     if (NULL != handle) {
         while (1) {
-            int xfer = (len > 4096) ? 4096 : len;
+            int xfer = (len > MAX_USBFS_BULK_SIZE) ? MAX_USBFS_BULK_SIZE : len;
 
 	        ret = AdbReadEndpointSync(handle->adb_read_pipe,
 	                              (void*)data,