diff --git a/.github/workflows/lib_compat_test.py b/.github/workflows/lib_compat_test.py
index 10460cc..d1dd918 100755
--- a/.github/workflows/lib_compat_test.py
+++ b/.github/workflows/lib_compat_test.py
@@ -9,67 +9,81 @@ import subprocess
 import sys
 
 parser = argparse.ArgumentParser()
-parser.add_argument('binary')
-parser.add_argument('--lib', action='append', default=[],
-                    help="Whitelist a library, e.g. GLIBC_2.18 or GLIBC")
-parser.add_argument('--sym', action='append', default=[],
-                    help="Whitelist a symbol, e.g. crc32")
+parser.add_argument("binary")
+parser.add_argument(
+    "--lib",
+    action="append",
+    default=[],
+    help="Whitelist a library, e.g. GLIBC_2.18 or GLIBC",
+)
+parser.add_argument(
+    "--sym", action="append", default=[], help="Whitelist a symbol, e.g. crc32"
+)
 args = parser.parse_args()
 
 # Parses GLIBC_2.3 into ("GLIBC", [2,3])
 # Parses GLIBC into ("GLIBC", None)
 def parse_version(version):
-  parts = version.rsplit('_', 1)
-  if len(parts) == 1:
-    return (version, None)
-  try:
-    return (parts[0], [int(p) for p in parts[1].split('.')])
-  except ValueError:
-    return (version, None)
+    parts = version.rsplit("_", 1)
+    if len(parts) == 1:
+        return (version, None)
+    try:
+        return (parts[0], [int(p) for p in parts[1].split(".")])
+    except ValueError:
+        return (version, None)
+
 
 lib_versions = dict([parse_version(v) for v in args.lib])
 
 # Determines whether all symbols with version 'lib' are acceptable.
 # A versioned library is name_x.y.z by convention.
 def accept_lib(lib):
-  (lib, ver) = parse_version(lib)
-  if not lib in lib_versions: # Non-whitelisted library.
-    return False
-  if lib_versions[lib] is None: # Unrestricted version
-    return True
-  if ver is None: # Lib has non-numeric version, library restricts version.
-    return False
-  return ver <= lib_versions[lib]
+    (lib, ver) = parse_version(lib)
+    if not lib in lib_versions:  # Non-whitelisted library.
+        return False
+    if lib_versions[lib] is None:  # Unrestricted version
+        return True
+    if ver is None:  # Lib has non-numeric version, library restricts version.
+        return False
+    return ver <= lib_versions[lib]
+
 
 # Determines whether an optionally-versioned symbol is acceptable.
 # A versioned symbol is symbol@version as output by nm.
 def accept_symbol(sym):
-  if sym in args.sym:
-    return True
-  split = sym.split('@', 1)
-  return (split[0] in args.sym) or (len(split) == 2 and accept_lib(split[1]))
+    if sym in args.sym:
+        return True
+    split = sym.split("@", 1)
+    return (split[0] in args.sym) or (len(split) == 2 and accept_lib(split[1]))
+
 
 # Run nm to find the undefined symbols, and check whether each is acceptable.
-nm = subprocess.run(['nm', '-uD', '--with-symbol-version', args.binary],
-                    stdout=subprocess.PIPE, text=True)
+nm = subprocess.run(
+    ["nm", "-uD", "--with-symbol-version", args.binary],
+    stdout=subprocess.PIPE,
+    text=True,
+)
 nm.check_returncode()
 status = 0
 for line in nm.stdout.splitlines():
-  # line = "       U foo@GLIBC_2.3"
-  parts = line.split()
-  if len(parts) != 2:
-    print("Unparseable nm output: ", line, file=sys.stderr)
-    status = 2
-    continue
-  if parts[0] == 'w': # Weak-undefined symbol, not actually required.
-    continue
-  if not accept_symbol(parts[1]):
-    print(parts[1])
-    status = 1
+    # line = "       U foo@GLIBC_2.3"
+    parts = line.split()
+    if len(parts) != 2:
+        print("Unparseable nm output: ", line, file=sys.stderr)
+        status = 2
+        continue
+    if parts[0] == "w":  # Weak-undefined symbol, not actually required.
+        continue
+    if not accept_symbol(parts[1]):
+        print(parts[1])
+        status = 1
 if status == 1:
-  print("Binary depends on disallowed symbols above. Use some combination of:\n"
+    print(
+        "Binary depends on disallowed symbols above. Use some combination of:\n"
         " - relax the whitelist by adding --lib and --sym flags to this test\n"
         " - force older symbol versions by updating lib_compat.h\n"
         " - avoid dynamic dependencies by changing CMake configuration\n"
-        " - remove bad dependencies from the code", file=sys.stderr)
+        " - remove bad dependencies from the code",
+        file=sys.stderr,
+    )
 sys.exit(status)