diff --git a/tools/check_elf_file.py b/tools/check_elf_file.py
index 0b80226..eaa1854 100755
--- a/tools/check_elf_file.py
+++ b/tools/check_elf_file.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Copyright (C) 2019 The Android Open Source Project
 #
@@ -196,11 +196,7 @@
   def _read_llvm_readobj(cls, elf_file_path, header, llvm_readobj):
     """Run llvm-readobj and parse the output."""
     cmd = [llvm_readobj, '--dynamic-table', '--dyn-symbols', elf_file_path]
-    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-    out, _ = proc.communicate()
-    rc = proc.returncode
-    if rc != 0:
-      raise subprocess.CalledProcessError(rc, cmd, out)
+    out = subprocess.check_output(cmd, text=True)
     lines = out.splitlines()
     return cls._parse_llvm_readobj(elf_file_path, header, lines)
 
@@ -467,7 +463,7 @@
     """Check whether all undefined symbols are resolved to a definition."""
     all_elf_files = [self._file_under_test] + self._shared_libs
     missing_symbols = []
-    for sym, imported_vers in self._file_under_test.imported.iteritems():
+    for sym, imported_vers in self._file_under_test.imported.items():
       for imported_ver in imported_vers:
         lib = self._find_symbol_from_libs(all_elf_files, sym, imported_ver)
         if not lib: