diff --git a/src/wikiq/__init__.py b/src/wikiq/__init__.py
index 169ec71..d45cad0 100755
--- a/src/wikiq/__init__.py
+++ b/src/wikiq/__init__.py
@@ -527,6 +527,7 @@ class WikiqParser:
         headings: bool = False,
         time_limit_seconds: Union[float, None] = None,
         max_revisions_per_file: int = 0,
+        input_filename: Union[str, None] = None,
     ):
         """
         Parameters:
@@ -535,8 +536,10 @@ class WikiqParser:
                           or a dict mapping namespace -> (pageid, revid) for partitioned output.
                           For single-file: skip all revisions up to and including this point.
            max_revisions_per_file : if > 0, close and rotate output files after this many revisions
+           input_filename : original input filename (needed for .jsonl.d output to derive output filename)
         """
         self.input_file = input_file
+        self.input_filename = input_filename
 
         self.collapse_user: bool = collapse_user
         self.persist: int = persist
@@ -845,13 +848,12 @@ class WikiqParser:
             if self.output_jsonl_dir:
                 # Create directory for JSONL output
                 Path(self.output_file).mkdir(parents=True, exist_ok=True)
-                part_num = 0
-                if self.resume_point is not None and len(self.resume_point) > 2:
-                    part_num = self.resume_point[2]
-                part_numbers[None] = part_num
-                jsonl_path = self._get_part_path(
-                    Path(self.output_file) / "data.jsonl", part_num
-                )
+                # Derive JSONL filename from input filename
+                if self.input_filename:
+                    jsonl_basename = os.path.basename(get_output_filename(self.input_filename, 'jsonl'))
+                else:
+                    jsonl_basename = "data.jsonl"
+                jsonl_path = Path(self.output_file) / jsonl_basename
                 writer = JSONLWriter(str(jsonl_path), schema, append=append_mode)
             else:
                 writer = JSONLWriter(self.output_file, schema, append=append_mode)
@@ -1527,6 +1529,7 @@ def main():
                 headings=args.headings,
                 time_limit_seconds=time_limit_seconds,
                 max_revisions_per_file=args.max_revisions_per_file,
+                input_filename=filename,
             )
 
             # Register signal handlers for graceful shutdown (CLI only)
diff --git a/test/test_resume.py b/test/test_resume.py
index 5dd8242..2684c7c 100644
--- a/test/test_resume.py
+++ b/test/test_resume.py
@@ -668,6 +668,88 @@ def test_resume_page_boundary():
     assert_frame_equal(df_full, df_resumed)
 
 
+def test_jsonl_dir_output():
+    """Test that .jsonl.d output creates files named after input files.
+
+    When output is a .jsonl.d directory, each input file should write to
+    a separate JSONL file named after the input (e.g., sailormoon.jsonl),
+    not a generic data.jsonl.
+    """
+    import pandas as pd
+    from pandas.testing import assert_frame_equal
+
+    output_dir = os.path.join(TEST_OUTPUT_DIR, "jsonl_dir_test.jsonl.d")
+    input_file = os.path.join(TEST_DIR, "dumps", f"{SAILORMOON}.xml.7z")
+
+    if os.path.exists(output_dir):
+        shutil.rmtree(output_dir)
+
+    # Run wikiq with .jsonl.d output
+    cmd = f"{WIKIQ} {input_file} -o {output_dir} --fandom-2020 --batch-size 10"
+    try:
+        subprocess.check_output(cmd, stderr=subprocess.PIPE, shell=True)
+    except subprocess.CalledProcessError as exc:
+        pytest.fail(exc.stderr.decode("utf8"))
+
+    # Verify output file is named after input, not "data.jsonl"
+    expected_output = os.path.join(output_dir, f"{SAILORMOON}.jsonl")
+    wrong_output = os.path.join(output_dir, "data.jsonl")
+
+    assert os.path.exists(expected_output), \
+        f"Expected {expected_output} to exist, but it doesn't. Directory contents: {os.listdir(output_dir)}"
+    assert not os.path.exists(wrong_output), \
+        f"Expected {wrong_output} NOT to exist (should be named after input file)"
+
+    # Verify output has data
+    rows = read_jsonl(expected_output)
+    assert len(rows) > 0, "Output file should have data"
+
+
+def test_jsonl_dir_resume():
+    """Test that resume works correctly with .jsonl.d directory output.
+
+    The resume logic must derive the same filename from the input file
+    as the write logic does.
+    """
+    import pandas as pd
+    from pandas.testing import assert_frame_equal
+
+    output_dir = os.path.join(TEST_OUTPUT_DIR, "jsonl_dir_resume.jsonl.d")
+    input_file = os.path.join(TEST_DIR, "dumps", f"{SAILORMOON}.xml.7z")
+
+    if os.path.exists(output_dir):
+        shutil.rmtree(output_dir)
+
+    # First run: complete
+    cmd_full = f"{WIKIQ} {input_file} -o {output_dir} --fandom-2020 --batch-size 10"
+    try:
+        subprocess.check_output(cmd_full, stderr=subprocess.PIPE, shell=True)
+    except subprocess.CalledProcessError as exc:
+        pytest.fail(exc.stderr.decode("utf8"))
+
+    expected_output = os.path.join(output_dir, f"{SAILORMOON}.jsonl")
+    full_rows = read_jsonl(expected_output)
+
+    # Truncate to partial
+    partial_idx = len(full_rows) // 2
+    with open(expected_output, 'w') as f:
+        for row in full_rows[:partial_idx]:
+            f.write(json.dumps(row) + "\n")
+
+    # Resume
+    cmd_resume = f"{WIKIQ} {input_file} -o {output_dir} --fandom-2020 --batch-size 10 --resume"
+    try:
+        subprocess.check_output(cmd_resume, stderr=subprocess.PIPE, shell=True)
+    except subprocess.CalledProcessError as exc:
+        pytest.fail(exc.stderr.decode("utf8"))
+
+    resumed_rows = read_jsonl(expected_output)
+
+    df_full = pd.DataFrame(full_rows)
+    df_resumed = pd.DataFrame(resumed_rows)
+    assert_frame_equal(df_full, df_resumed)
+
+
 def test_resume_revert_detection():
     """Test that revert detection works correctly after resume.