diff --git a/compiler-rt/lib/asan/scripts/asan_symbolize.py b/compiler-rt/lib/asan/scripts/asan_symbolize.py
index 5c4001acf8c653..ab04b1c67e5a8a 100755
--- a/compiler-rt/lib/asan/scripts/asan_symbolize.py
+++ b/compiler-rt/lib/asan/scripts/asan_symbolize.py
@@ -208,7 +208,7 @@ def symbolize(self, addr, binary, offset):
       # EPIPE happens if addr2line exits early (which some implementations do
       # if an invalid file is passed).
       if e.errno == errno.EPIPE:
-        logging.debug("addr2line exited early (broken pipe), returncode=%d" % self.pipe.poll())
+        logging.debug(f"addr2line exited early (broken pipe) returncode={self.pipe.poll()}")
       else:
         logging.debug("unexpected I/O exception communicating with addr2line", exc_info=e)
       lines.append(('??', '??:0'))