diff --git a/.ci/make_and_test.sh b/.ci/make_and_test.sh
index e05ae140..6aec305e 100755
--- a/.ci/make_and_test.sh
+++ b/.ci/make_and_test.sh
@@ -8,7 +8,7 @@ set -evx
 
 mkdir -p build
 cd build
-cmake .. -DCLI11_CXX_STD=$STD -DCLI11_SINGLE_FILE_TESTS=ON -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_COMPILER_LAUNCHER=ccache $@
+cmake .. -DCLI11_SINGLE_FILE=ON -DCLI11_CXX_STD=$STD -DCLI11_SINGLE_FILE_TESTS=ON -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_COMPILER_LAUNCHER=ccache $@
 cmake --build . -- -j2
 
 set +evx
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 85b16905..363ce19c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -112,33 +112,16 @@ export(TARGETS CLI11
 # Register in the user cmake package registry
 export(PACKAGE CLI11)
 
-# Single file test
-if(CMAKE_VERSION VERSION_LESS 3.12)
-    set(Python_ADDITIONAL_VERSIONS 2.7 3.4 3.5 3.6 3.7 3.8)
-    find_package(PythonInterp)
-    set(Python_VERSION ${PYTHON_VERSION_STRING})
-    set(Python_EXECUTABLE "${PYTHON_EXECUTABLE}")
-else()
-    find_package(Python)
-endif()
-
-if(Python_Interpreter_FOUND OR PYTHONINTERP_FOUND)
-    if(Python_VERSION VERSION_LESS 2.7)
-        set(CLI11_PYTHON_FOUND FALSE)
-    else()
-        set(CLI11_PYTHON_FOUND TRUE)
-    endif()
-else()
-    set(CLI11_PYTHON_FOUND FALSE)
-endif()
-
-cmake_dependent_option(CLI11_SINGLE_FILE "Generate a single header file" ON "CUR_PROJ;CLI11_PYTHON_FOUND" OFF)
+option(CLI11_SINGLE_FILE "Generate a single header file" OFF)
 
 if(CLI11_SINGLE_FILE)
-    if(NOT CLI11_PYTHON_FOUND)
-        message(FATAL_ERROR "CLI11_SINGLE_FILE requires Python 2.7 or 3 (not found)")
+# Single file test
+    if(CMAKE_VERSION VERSION_LESS 3.12)
+        find_package(PythonInterp REQUIRED)
+        set(Python_VERSION ${PYTHON_VERSION_STRING})
+        set(Python_EXECUTABLE "${PYTHON_EXECUTABLE}")
     else()
-        message(STATUS "Building single file include using Python ${Python_VERSION} at ${Python_EXECUTABLE}")
+        find_package(Python REQUIRED)
     endif()
 
     file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/include")
diff --git a/LICENSE b/LICENSE
index d3d8f012..6b007783 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-CLI11 1.5 Copyright (c) 2017-2018 University of Cincinnati, developed by Henry
+CLI11 1.6 Copyright (c) 2017-2018 University of Cincinnati, developed by Henry
 Schreiner under NSF AWARD 1414736. All rights reserved.
 
 Redistribution and use in source and binary forms of CLI11, with or without
diff --git a/scripts/MakeSingleHeader.py b/scripts/MakeSingleHeader.py
index 56e875d0..b474864d 100755
--- a/scripts/MakeSingleHeader.py
+++ b/scripts/MakeSingleHeader.py
@@ -9,7 +9,7 @@ import operator
 from copy import copy
 from functools import reduce
 
-import subprocess
+from subprocess import Popen, PIPE
 
 includes_local = re.compile(r"""^#include "(.*)"$""", re.MULTILINE)
 includes_system = re.compile(r"""^#include \<(.*)\>$""", re.MULTILINE)
@@ -112,12 +112,13 @@ class HeaderFile(object):
 def MakeHeader(output, main_header, include_dir = '../include', namespace=None, macro=None):
     # Set tag if possible to class variable
     try:
-        proc = subprocess.Popen(['git', 'describe', '--tags', '--always'], cwd=str(DIR), stdout=subprocess.PIPE)
+        proc = Popen(['git', 'describe', '--tags', '--always'], cwd=str(DIR), stdout=PIPE)
         out, _ = proc.communicate()
-        if proc.returncode == 0:
-            HeaderFile.TAG = out.decode("utf-8").strip()
     except OSError:
         pass
+    else:
+        if proc.returncode == 0:
+            HeaderFile.TAG = out.decode("utf-8").strip()
 
     base_dir = os.path.abspath(os.path.join(DIR, include_dir))
     main_header = os.path.join(base_dir, main_header)