diff --git a/tools/mavplayback.py b/tools/mavplayback.py
index 73f9d833d..f744683c3 100755
--- a/tools/mavplayback.py
+++ b/tools/mavplayback.py
@@ -18,6 +18,7 @@
 import tkinter
 
 from pymavlink import fgFDM
+from pymavlink import DFReader
 
 from argparse import ArgumentParser
 parser = ArgumentParser(description=__doc__)
@@ -57,6 +58,10 @@ def __init__(self, filename):
 
         self.mlog = mavutil.mavlink_connection(filename, planner_format=args.planner,
                                                robust_parsing=True)
+        if isinstance(self.mlog, DFReader.DFReader_binary):
+            print("mavplayback.py only works on .tlog files, not BIN ('dataflash') files")
+            sys.exit(1)
+
         self.mout = []
         for m in args.out:
             self.mout.append(mavutil.mavlink_connection(m, input=False, baud=args.baudrate))