diff --git a/src/pkgmgr/actions/release/files/changelog_md.py b/src/pkgmgr/actions/release/files/changelog_md.py
index 142f9d8..0cc4e61 100644
--- a/src/pkgmgr/actions/release/files/changelog_md.py
+++ b/src/pkgmgr/actions/release/files/changelog_md.py
@@ -16,6 +16,11 @@ H1_RE = re.compile(r"^#\s+\S", re.MULTILINE)
 H2_RE = re.compile(r"^##\s+\S", re.MULTILINE)
 
 
+def _at_end_of_file(entry: str) -> str:
+    """Return *entry* without the blank line that separates it from a next one."""
+    return entry.rstrip("\n") + "\n"
+
+
 def _insert_after_h1(existing: str, entry: str) -> str:
     """Place *entry* after the H1 (and any intro prose), above the first H2.
 
@@ -26,7 +31,7 @@ def _insert_after_h1(existing: str, entry: str) -> str:
     ``## ``) is preserved: *entry* is prepended unchanged.
     """
     if not existing.strip():
-        return f"# Changelog\n\n{entry}"
+        return f"# Changelog\n\n{_at_end_of_file(entry)}"
 
     if not H1_RE.search(existing):
         # Legacy layout: file starts with `## [version]` and has no H1.
@@ -43,7 +48,7 @@ def _insert_after_h1(existing: str, entry: str) -> str:
             if existing.endswith("\n\n")
             else ("\n" if existing.endswith("\n") else "\n\n")
         )
-        return f"{existing}{suffix}{entry}"
+        return f"{existing}{suffix}{_at_end_of_file(entry)}"
 
     # Insert new entry just before the first H2.
     head = existing[: h2_match.start()].rstrip("\n") + "\n\n"
diff --git a/tests/unit/pkgmgr/actions/release/test_changelog_md.py b/tests/unit/pkgmgr/actions/release/test_changelog_md.py
new file mode 100644
index 0000000..f22b341
--- /dev/null
+++ b/tests/unit/pkgmgr/actions/release/test_changelog_md.py
@@ -0,0 +1,41 @@
+from __future__ import annotations
+
+import unittest
+
+from pkgmgr.actions.release.files.changelog_md import _insert_after_h1
+
+ENTRY = "## [1.0.0] - 2026-09-18\n\nOfficial Release\n\n"
+
+
+class TestInsertAfterH1(unittest.TestCase):
+    def _assert_lint_clean(self, document: str) -> None:
+        self.assertNotIn(
+            "\n\n\n",
+            document,
+            f"MD012: multiple consecutive blank lines in\n{document!r}",
+        )
+        self.assertTrue(
+            document.endswith("\n") and not document.endswith("\n\n"),
+            f"MD012: blank line at end of file in\n{document!r}",
+        )
+
+    def test_an_empty_changelog_gets_one_trailing_newline(self) -> None:
+        self._assert_lint_clean(_insert_after_h1("", ENTRY))
+
+    def test_a_first_entry_under_a_bare_h1_gets_one_trailing_newline(self) -> None:
+        self._assert_lint_clean(_insert_after_h1("# Changelog\n", ENTRY))
+
+    def test_a_second_entry_stays_separated_from_the_first(self) -> None:
+        existing = "# Changelog\n\n## [0.9.0] - 2026-09-01\n\nOlder\n"
+        document = _insert_after_h1(existing, ENTRY)
+        self._assert_lint_clean(document)
+        self.assertIn("Official Release\n\n## [0.9.0]", document)
+
+    def test_a_legacy_headerless_changelog_gains_an_h1(self) -> None:
+        document = _insert_after_h1("## [0.9.0] - 2026-09-01\n\nOlder\n", ENTRY)
+        self._assert_lint_clean(document)
+        self.assertTrue(document.startswith("# Changelog\n\n## [1.0.0]"))
+
+
+if __name__ == "__main__":
+    unittest.main()