diff --git a/version.py b/version.py
index 617da3f..029c90f 100644
--- a/version.py
+++ b/version.py
@@ -6,11 +6,12 @@
 """
 import re
 import sys
-import importlib
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 from pathlib import Path
 
 PACKAGE_NAME = "jsonobject"
+PACKAGE_PATH = Path(__file__).parent / PACKAGE_NAME / "__init__.py"
+V_EXPR = re.compile(r"""(?<=^__version__ = )['"](.+)['"]$""", flags=re.M)
 
 
 def main(argv=sys.argv):
@@ -24,12 +25,12 @@ def main(argv=sys.argv):
 
 
 def check(ref):
-    pkg = importlib.import_module(PACKAGE_NAME)
     if not ref.startswith("refs/tags/v"):
         sys.exit(f"unexpected ref: {ref}")
-    version = ref.removeprefix("refs/tags/v")
-    if version != pkg.__version__:
-        sys.exit(f"version mismatch: {version} != {pkg.__version__}")
+    tag_version = ref.removeprefix("refs/tags/v")
+    pkg_version = parse_version(get_module_text())
+    if tag_version != pkg_version:
+        sys.exit(f"version mismatch: {tag_version} != {pkg_version}")
 
 
 def update(sha=""):
@@ -40,21 +41,26 @@ def update(sha=""):
     updating the version for a PyPI release.
     PyPI error: The use of local versions ... is not allowed
     """
-    path = Path(__file__).parent / PACKAGE_NAME / "__init__.py"
-    vexpr = re.compile(r"""(?<=^__version__ = )['"](.+)['"]$""", flags=re.M)
-    with open(path, "r+") as file:
-        text = file.read()
-        match = vexpr.search(text)
-        if not match:
-            sys.exit(f"{PACKAGE_NAME}.__version__ not found")
-        devv = datetime.now(UTC).strftime("%Y%m%d%H%M%S")
-        if sha:
-            devv += f"+{sha[:7]}"
-        version = f"{match.group(1)}.dev{devv}"
-        print("new version:", version)
-        file.seek(0)
-        file.write(vexpr.sub(repr(version), text))
-        file.truncate()
+    devv = datetime.now(timezone.utc).strftime("%Y%m%d%H%M%S")
+    if sha:
+        devv += f"+{sha[:7]}"
+    module_text = get_module_text()
+    version = f"{parse_version(module_text)}.dev{devv}"
+    print("new version:", version)
+    with open(PACKAGE_PATH, "w") as file:
+        file.write(V_EXPR.sub(repr(version), module_text))
+
+
+def get_module_text():
+    with open(PACKAGE_PATH, "r") as file:
+        return file.read()
+
+
+def parse_version(module_text):
+    match = V_EXPR.search(module_text)
+    if not match:
+        sys.exit(f"{PACKAGE_NAME}.__version__ not found")
+    return match.group(1)
 
 
 COMMANDS = {"check": check, "update": update}