diff --git a/ports/stm32/boards/plli2svalues.py b/ports/stm32/boards/plli2svalues.py
index f872c60ebb5c5..8fdf6c0d7a187 100644
--- a/ports/stm32/boards/plli2svalues.py
+++ b/ports/stm32/boards/plli2svalues.py
@@ -4,6 +4,7 @@
 Those processors are listed below in the mcu_support_plli2s[] list.
 """
 
+import gzip
 import re
 from collections import namedtuple
 
@@ -129,7 +130,7 @@ def generate_c_table(plli2s_table, hse, pllm):
 def search_header(filename, re_define, lookup):
     regex_define = re.compile(re_define)
     val = None
-    with open(filename) as f:
+    with gzip.open(filename, "rt") as f:
         for line in f:
             line = line.strip()
             m = regex_define.match(line)
diff --git a/ports/stm32/boards/pllvalues.py b/ports/stm32/boards/pllvalues.py
index 5558d04c5b9e1..2e607861e24b5 100644
--- a/ports/stm32/boards/pllvalues.py
+++ b/ports/stm32/boards/pllvalues.py
@@ -4,6 +4,7 @@
 for the machine.freq() function.
 """
 
+import gzip
 import re
 
 
@@ -231,7 +232,7 @@ def search_header_for_hsx_values(filename):
     regex_def = re.compile(
         r"static.* +(micropy_hw_hs[ei]_value) = +([0-9 +-/\*()]+);",
     )
-    with open(filename) as f:
+    with gzip.open(filename, "rt") as f:
         for line in f:
             line = line.strip()
             m = regex_def.match(line)
diff --git a/py/makeqstrdefs.py b/py/makeqstrdefs.py
index dd514c7033dd7..1f7bbc67a4689 100644
--- a/py/makeqstrdefs.py
+++ b/py/makeqstrdefs.py
@@ -5,7 +5,7 @@
 This script works with Python 3.3+.
 """
 
-import io
+import gzip
 import os
 import re
 import subprocess
@@ -71,7 +71,7 @@ def run(files):
     except NotImplementedError:
         cpus = 1
     p = multiprocessing.dummy.Pool(cpus)
-    with open(args.output[0], "wb") as out_file:
+    with gzip.open(args.output[0], "wb", compresslevel=1) as out_file:
         for flags, sources in (
             (args.cflags, csources),
             (args.cxxflags, cxxsources),
@@ -230,7 +230,7 @@ class Args:
         pass
 
     if args.command == "split":
-        with io.open(args.input_filename, encoding="utf-8") as infile:
+        with gzip.open(args.input_filename, "rt", encoding="utf-8") as infile:
             process_file(infile)
 
     if args.command == "cat":