diff --git a/parser/parser.py b/parser/parser.py
index a41b790..094a828 100644
--- a/parser/parser.py
+++ b/parser/parser.py
@@ -98,6 +98,24 @@ def merge_meta(idl: dict, meta_path: Path) -> dict:
     return idl
 
 
+#: The directories of MobilityDB's header tree holding a stand-in for the header of a
+#: library a build may lack. MobilityDB's build reads `geos-none/geos_c.h` only where GEOS
+#: is absent, and installs it then in place of GEOS's own `geos_c.h`
+#: (`meos/CMakeLists.txt`, under `if(NOT GEOS)`), so no installed header tree holds both.
+#: What a stand-in declares is that library's API rather than MEOS's, and read beside the
+#: library's own header, which `meos_internal_geo.h` includes, every type it declares is a
+#: redefinition clang drops: its enums would enter the catalog nameless and valueless.
+STAND_IN_DIRS = frozenset({"geos-none"})
+
+
+def meos_headers(headers_dir: Path) -> list[Path]:
+    """The headers of the tree the parse reads, in order: those an install of MEOS ships,
+    the tree's own less its stand-ins (#STAND_IN_DIRS) for a library's header. It is the one
+    list #build_entry_point includes and #parse_meos owns, so the two read the same tree."""
+    return sorted(h for h in headers_dir.glob("**/*.h")
+                  if not STAND_IN_DIRS & set(h.relative_to(headers_dir).parts[:-1]))
+
+
 def parse_meos(entry: Path, include_dir: Path,
                extra_headers: tuple[Path, ...] = ()) -> dict:
     index = clang.cindex.Index.create()
@@ -129,7 +147,7 @@ def parse_meos(entry: Path, include_dir: Path,
         options=clang.cindex.TranslationUnit.PARSE_DETAILED_PROCESSING_RECORD)
 
     # Collect all .h files belonging to the project
-    own_files = {str(p.resolve()) for p in include_dir.glob("**/*.h")}
+    own_files = {str(p.resolve()) for p in meos_headers(include_dir)}
     own_files.update(str(h.resolve()) for h in extra_headers)
 
     # First pass: build a mapping "anonymous struct location -> typedef name", and
@@ -226,7 +244,7 @@ def _dedup_structs(items: list) -> list:
 def build_entry_point(headers_dir: Path,
                       extra_headers: tuple[Path, ...] = ()) -> str:
     lines = []
-    for h in sorted(headers_dir.glob("**/*.h")):
+    for h in meos_headers(headers_dir):
         lines.append(f'#include "{h.resolve()}"')
     for h in extra_headers:
         lines.append(f'#include "{h.resolve()}"')
diff --git a/tests/test_stand_in_headers.py b/tests/test_stand_in_headers.py
new file mode 100644
index 0000000..abdd8ef
--- /dev/null
+++ b/tests/test_stand_in_headers.py
@@ -0,0 +1,63 @@
+"""Regression tests for the headers the catalog parse reads.
+
+MobilityDB's header tree holds `geos-none/geos_c.h`, a stand-in its build reads only where
+GEOS is absent and installs then in place of GEOS's own `geos_c.h`. Parsed beside the
+library's header, which `meos_internal_geo.h` includes, every enum it declares is a
+redefinition clang drops: the catalog carried `enum (unnamed at .../geos_c.h:84:6)` with no
+value, and a binding writing one Java enum per catalog enum (JMEOS `FunctionsGenerator`)
+failed opening a file of that name. #meos_headers of parser/parser.py leaves the stand-in
+out, as an install of MEOS does, so the catalog states neither its enums nor its functions.
+
+The catalog half mirrors #StructLayoutTests of tests/test_struct_layout.py: it reads the
+generated IDL and skips where there is none; run ``python run.py`` first.
+"""
+import json
+import re
+import tempfile
+import unittest
+from pathlib import Path
+
+from parser.parser import meos_headers, build_entry_point
+
+IDL = Path(__file__).resolve().parents[1] / "output" / "meos-idl.json"
+C_IDENTIFIER = re.compile(r"^[A-Za-z_][A-Za-z0-9_]*$")
+
+
+class StandInHeaderTests(unittest.TestCase):
+    def test_the_stand_in_directory_is_not_read(self):
+        with tempfile.TemporaryDirectory() as d:
+            root = Path(d)
+            for rel in ("meos.h", "geo/postgis_funcs.h", "geos-none/geos_c.h"):
+                (root / rel).parent.mkdir(parents=True, exist_ok=True)
+                (root / rel).write_text("")
+            read = [h.relative_to(root).as_posix() for h in meos_headers(root)]
+            self.assertEqual(read, ["geo/postgis_funcs.h", "meos.h"])
+            self.assertNotIn("geos-none", build_entry_point(root))
+
+    def test_a_header_named_like_the_stand_in_elsewhere_is_read(self):
+        with tempfile.TemporaryDirectory() as d:
+            root = Path(d)
+            (root / "geo").mkdir()
+            (root / "geo" / "geos-none.h").write_text("")
+            self.assertEqual([h.name for h in meos_headers(root)], ["geos-none.h"])
+
+
+class CatalogEnumNameTests(unittest.TestCase):
+    def setUp(self):
+        if not IDL.exists():
+            self.skipTest(f"{IDL} not generated; run `python run.py` first")
+        self.idl = json.loads(IDL.read_text())
+
+    def test_every_enum_is_named_and_carries_values(self):
+        for e in self.idl["enums"]:
+            self.assertRegex(e["name"], C_IDENTIFIER, e["name"])
+            self.assertTrue(e["values"], e["name"])
+
+    def test_no_declaration_comes_from_the_stand_in(self):
+        for section in ("functions", "structs", "enums"):
+            files = {x.get("file") for x in self.idl[section]}
+            self.assertNotIn("geos_c.h", files, section)
+
+
+if __name__ == "__main__":
+    unittest.main()