diff --git a/buildscripts/mongosymb.py b/buildscripts/mongosymb.py
index a8544cdf92..7ad3eef782 100755
--- a/buildscripts/mongosymb.py
+++ b/buildscripts/mongosymb.py
@@ -20,6 +20,7 @@ but emits json instead of plain text.
 import json
 import argparse
 import os
+import signal
 import subprocess
 import sys
 
@@ -210,6 +211,7 @@ def make_argument_parser(parser=None, **kwargs):
     parser.add_argument('--src-dir-to-move', action="store", type=str, default=None,
                         help="Specify a src dir to move to /data/mci/{original_buildid}/src")
 
+    parser.add_argument('--live', action='store_true')
     s3_group = parser.add_argument_group(
         "s3 options", description='Options used with \'--debug-file-resolver s3\'')
     s3_group.add_argument('--s3-cache-dir')
@@ -219,10 +221,38 @@ def make_argument_parser(parser=None, **kwargs):
     parser.add_argument('path_to_executable', nargs="?")
     return parser
 
+def substitute_stdin(options):
+    # Ignore Ctrl-C. When the process feeding the pipe exits, `stdin` will be closed.
+    signal.signal(signal.SIGINT, signal.SIG_IGN)
+
+    while True:
+        line = os.sys.stdin.readline()
+        if not line:
+            return
+
+        line = line.rstrip()
+
+        if 'Frame: 0x' in line:
+            continue
+
+        if '{"backtrace":' in line:
+            prefix = line[:line.index('{"backtrace":')]
+            backtrace = line[line.index('{"backtrace":'):]
+            traceDoc = json.JSONDecoder().raw_decode(backtrace)[0]
+            frames = symbolize_frames(traceDoc, PathDbgFileResolver(options.path_to_executable), options.symbolizer_path, [], 'classic')
+            print(prefix)
+            classic_output(frames, os.sys.stdout, indent=2)
+        else:
+            print(line)
 
 def main(options):
     """Execute Main program."""
 
+    if options.live:
+        print(options)
+        substitute_stdin(options)
+        sys.exit(0)
+
     # Skip over everything before the first '{' since it is likely to be log line prefixes.
     # Additionally, using raw_decode() to ignore extra data after the closing '}' to allow maximal
     # sloppiness in copy-pasting input.