diff --git a/wpiformat/README.rst b/wpiformat/README.rst
index f164953b..14d87391 100644
--- a/wpiformat/README.rst
+++ b/wpiformat/README.rst
@@ -6,7 +6,7 @@ Provides linters and formatters for ensuring WPILib's C++, Java, and Python code
 Dependencies
 ************
 
-- `Python 3.5 or newer <https://www.python.org/downloads/>`_
+- `Python 3.6 or newer <https://www.python.org/downloads/>`_
 - clang-format (included with `LLVM <http://llvm.org/releases/download.html>`_)
 
 To obtain newer versions of clang-format on older Debian and Ubuntu releases, either upgrade to one that does or add the appropriate ``deb ... main`` line from `apt.llvm.org <http://apt.llvm.org/>`_ to ``/etc/apt/sources.list``. Then install ``clang-format-#`` where ``#`` is the version number.
diff --git a/wpiformat/wpiformat/__init__.py b/wpiformat/wpiformat/__init__.py
index d1115c66..c98a85b4 100644
--- a/wpiformat/wpiformat/__init__.py
+++ b/wpiformat/wpiformat/__init__.py
@@ -36,10 +36,14 @@ def filter_ignored_files(names):
     # Windows, so os.linesep isn't used here.
     encoded_names = "\n".join(names).encode()
 
-    output_list = subprocess.run(
+    proc = subprocess.run(
         ["git", "check-ignore", "--no-index", "-n", "-v", "--stdin"],
         input=encoded_names,
-        stdout=subprocess.PIPE).stdout.decode().split("\n")
+        stdout=subprocess.PIPE)
+    if proc.returncode == 128:
+        raise subprocess.CalledProcessError
+
+    output_list = proc.stdout.decode().split("\n")
 
     # "git check-ignore" prefixes the names of non-ignored files with "::",
     # wraps names in quotes on Windows, and outputs "\n" line separators on all
@@ -303,13 +307,11 @@ def main():
     files = filter_ignored_files(files)
 
     # Create list of all changed files
-    changed_file_list = []
-
-    output_list = subprocess.run(["git", "diff", "--name-only", "master"],
-                                 stdout=subprocess.PIPE).stdout.split()
-    for line in output_list:
-        changed_file_list.append(root_path + os.sep +
-                                 line.strip().decode("ascii"))
+    output_list = subprocess.check_output(
+        ["git", "diff", "--name-only", "master"], encoding="ascii").split()
+    changed_file_list = [
+        root_path + os.sep + line.strip() for line in output_list
+    ]
 
     # Don't run tasks on modifiable or generated files
     work = []
diff --git a/wpiformat/wpiformat/licenseupdate.py b/wpiformat/wpiformat/licenseupdate.py
index 912b02b5..baa0e012 100644
--- a/wpiformat/wpiformat/licenseupdate.py
+++ b/wpiformat/wpiformat/licenseupdate.py
@@ -137,13 +137,12 @@ def run_pipeline(self, config_file, name, lines):
         # log" because the year the file was last modified in the history should
         # be used. Author dates can be older than this or even out of order in
         # the log.
-        cmd = ["git", "log", "-n", "1", "--format=%ci", "--", name]
-        last_year = subprocess.run(cmd,
-                                   stdout=subprocess.PIPE).stdout.decode()[:4]
+        last_year = subprocess.check_output(
+            ["git", "log", "-n", "1", "--format=%ci", "--", name]).decode()[:4]
 
         # Check if file has uncomitted changes in the working directory
-        cmd = ["git", "diff-index", "--quiet", "HEAD", "--", name]
-        has_uncommitted_changes = subprocess.run(cmd).returncode
+        has_uncommitted_changes = subprocess.run(
+            ["git", "diff-index", "--quiet", "HEAD", "--", name]).returncode
 
         # If file hasn't been committed yet or has changes in the working
         # directory, use current calendar year as end of copyright year range