diff --git a/specfile/specfile.py b/specfile/specfile.py
index 385986a..d5120ec 100644
--- a/specfile/specfile.py
+++ b/specfile/specfile.py
@@ -12,7 +12,11 @@
 
 from specfile.changelog import Changelog, ChangelogEntry, guess_packager
 from specfile.context_management import ContextManager
-from specfile.exceptions import SourceNumberException, SpecfileException
+from specfile.exceptions import (
+    SourceNumberException,
+    SpecfileException,
+    UnterminatedMacroException,
+)
 from specfile.formatter import formatted
 from specfile.macro_definitions import (
     CommentOutStyle,
@@ -433,12 +437,16 @@ def contains_autochangelog(section: Section) -> bool:
             if line.lstrip().startswith("#"):
                 # skip comments
                 continue
-            for node in ValueParser.flatten(ValueParser.parse(line)):
-                if (
-                    isinstance(node, (MacroSubstitution, EnclosedMacroSubstitution))
-                    and node.name == "autochangelog"
-                ):
-                    return True
+            try:
+                for node in ValueParser.flatten(ValueParser.parse(line)):
+                    if (
+                        isinstance(node, (MacroSubstitution, EnclosedMacroSubstitution))
+                        and node.name == "autochangelog"
+                    ):
+                        return True
+            except UnterminatedMacroException:
+                # ignore unparseable lines
+                continue
         return False
 
     @property
diff --git a/tests/integration/test_specfile.py b/tests/integration/test_specfile.py
index b047c28..bc6f2c1 100644
--- a/tests/integration/test_specfile.py
+++ b/tests/integration/test_specfile.py
@@ -329,7 +329,9 @@ def test_autorelease(spec_rpmautospec, raw_release, has_autorelease):
 @pytest.mark.skipif(
     rpm.__version__ < "4.16", reason="%autochangelog requires rpm 4.16 or higher"
 )
-def test_autochangelog(spec_rpmautospec, spec_conditionalized_changelog):
+def test_autochangelog(
+    spec_rpmautospec, spec_conditionalized_changelog, spec_autosetup
+):
     spec = Specfile(spec_rpmautospec)
     assert spec.has_autochangelog
     with spec.changelog() as changelog:
@@ -350,6 +352,10 @@ def test_autochangelog(spec_rpmautospec, spec_conditionalized_changelog):
     assert changelogs[0] == changelog
     with spec.changelog(changelogs[1]) as changelog:
         assert changelog[-1].content == ["test"]
+    spec = Specfile(spec_autosetup)
+    with spec.changelog() as changelog:
+        changelog[0].content += "%"
+    assert not spec.has_autochangelog
 
 
 @pytest.mark.skipif(