diff --git a/pupy/packages/all/pupyutils/basic_cmds.py b/pupy/packages/all/pupyutils/basic_cmds.py
index fc0ea669..9f4a7f2c 100644
--- a/pupy/packages/all/pupyutils/basic_cmds.py
+++ b/pupy/packages/all/pupyutils/basic_cmds.py
@@ -644,19 +644,10 @@ def cat(path, N, n, grep, encoding=None, filter_out=False):
                             if n and len(data) >= n:
                                 break
                     else:
-                        try:
-                            fin.seek(0, os.SEEK_END)
-                            file_size = fin.tell()
-                            fin.seek(0)
-                            block_size = 4*8192
-                            block = fin.read(block_size)
-                            if file_size > block_size:
-                                block += "\n[FILE TRUNCATED, USE DOWNLOAD]"
-                        except IOError as e:
-                            if e.errno != errno.EINVAL:
-                                # File does not support seek
-                                raise
-                            block = fin.read()
+                        block_size = 4*8192
+                        block = fin.read(block_size)
+                        if len(block) == block_size:
+                            block += "\n[FILE TRUNCATED, USE DOWNLOAD]"
 
                         return block
             else: