diff --git a/tools/pyboard.py b/tools/pyboard.py
index 6376b13c7..c97ddbe48 100755
--- a/tools/pyboard.py
+++ b/tools/pyboard.py
@@ -70,6 +70,7 @@ Or:
 import sys
 import time
 import os
+import ast
 
 try:
     stdout = sys.stdout.buffer
@@ -426,7 +427,12 @@ class Pyboard:
                 data = bytearray()
                 self.exec_("print(r(%u))" % chunk_size, data_consumer=lambda d: data.extend(d))
                 assert data.endswith(b"\r\n\x04")
-                data = eval(str(data[:-3], "ascii"))
+                try:
+                    data = ast.literal_eval(str(data[:-3], "ascii"))
+                    if not isinstance(data, bytes):
+                        raise ValueError("Not bytes")
+                except (UnicodeError, ValueError) as e:
+                    raise PyboardError("fs_get: Could not interpret received data: %s" % str(e))
                 if not data:
                     break
                 f.write(data)