diff --git a/util/decode_packet_trace.py b/util/decode_packet_trace.py
index e3486e63a6..21d7f9a157 100755
--- a/util/decode_packet_trace.py
+++ b/util/decode_packet_trace.py
@@ -63,7 +63,7 @@ def main():
         exit(-1)
 
     # Read the magic number in 4-byte Little Endian
-    magic_number = proto_in.read(4)
+    magic_number = proto_in.read(4).decode()
 
     if magic_number != "gem5":
         print("Unrecognized file", sys.argv[1])