diff --git a/tdd-ai-agents/tests/test_core.py b/tdd-ai-agents/tests/test_core.py
index 21f288a849..1d5c73b93d 100644
--- a/tdd-ai-agents/tests/test_core.py
+++ b/tdd-ai-agents/tests/test_core.py
@@ -26,6 +26,18 @@ def test_double_digit_segments_sort_numerically():
     assert Version("3.9") < Version("3.10")
 
 
+@pytest.mark.parametrize(
+    "shorter, longer",
+    [
+        ("1.2", "1.2.0"),
+        ("1", "1.0.0"),
+        ("1.0a1", "1.0.0a1"),
+    ],
+)
+def test_missing_segments_count_as_zero(shorter, longer):
+    assert Version(shorter) == Version(longer)
+
+
 @pytest.mark.parametrize(
     "lower, higher",
     [
diff --git a/tdd-ai-agents/version_check/core.py b/tdd-ai-agents/version_check/core.py
index d4cfbc2480..39150427b2 100644
--- a/tdd-ai-agents/version_check/core.py
+++ b/tdd-ai-agents/version_check/core.py
@@ -27,6 +27,9 @@ def __init__(self, text):
         self._dev = int(match["dev"]) if match["dev"] else None
 
     def _key(self):
+        release = self._release
+        while len(release) > 1 and release[-1] == 0:
+            release = release[:-1]
         if self._dev is not None and self._pre is None:
             phase = (0, self._dev)
         elif self._pre is not None:
@@ -35,7 +38,7 @@ def _key(self):
             phase = (3, self._post)
         else:
             phase = (2, 0)
-        return (self._release, phase)
+        return (release, phase)
 
     def __eq__(self, other):
         if not isinstance(other, Version):