diff --git a/doc/whatsnew/fragments/9343.bugfix b/doc/whatsnew/fragments/9343.bugfix
new file mode 100644
index 0000000000..bdae77d6ff
--- /dev/null
+++ b/doc/whatsnew/fragments/9343.bugfix
@@ -0,0 +1,3 @@
+Fixed a crash in ``symilar`` when the ``-d`` option was not properly recognized.
+
+Closes #9343
diff --git a/pylint/checkers/similar.py b/pylint/checkers/similar.py
index b06b9d707f..40eba0bb15 100644
--- a/pylint/checkers/similar.py
+++ b/pylint/checkers/similar.py
@@ -39,7 +39,7 @@
 import warnings
 from collections import defaultdict
 from collections.abc import Callable, Generator, Iterable, Sequence
-from getopt import getopt
+from getopt import GetoptError, getopt
 from io import BufferedIOBase, BufferedReader, BytesIO
 from itertools import chain
 from typing import (
@@ -921,10 +921,18 @@ def Run(argv: Sequence[str] | None = None) -> NoReturn:
     ignore_docstrings = False
     ignore_imports = False
     ignore_signatures = False
-    opts, args = getopt(list(argv), s_opts, l_opts)
+    try:
+        opts, args = getopt(list(argv), s_opts, l_opts)
+    except GetoptError as e:
+        print(e)
+        usage(2)
     for opt, val in opts:
         if opt in {"-d", "--duplicates"}:
-            min_lines = int(val)
+            try:
+                min_lines = int(val)
+            except ValueError as e:
+                print(e)
+                usage(2)
         elif opt in {"-h", "--help"}:
             usage()
         elif opt in {"-i", "--ignore-comments"}:
diff --git a/tests/checkers/unittest_similar.py b/tests/checkers/unittest_similar.py
index 8c00faee54..30279bf966 100644
--- a/tests/checkers/unittest_similar.py
+++ b/tests/checkers/unittest_similar.py
@@ -497,3 +497,32 @@ def test_set_duplicate_lines_to_zero() -> None:
         similar.Run(["--duplicates=0", SIMILAR1, SIMILAR2])
     assert ex.value.code == 0
     assert output.getvalue() == ""
+
+
+@pytest.mark.parametrize("v", ["d", "i"])
+def test_bad_equal_short_form_option(v: str) -> None:
+    """Regression test for https://github.com/pylint-dev/pylint/issues/9343"""
+    output = StringIO()
+    with redirect_stdout(output), pytest.raises(SystemExit) as ex:
+        similar.Run([f"-{v}=0", SIMILAR1, SIMILAR2])
+    assert ex.value.code == 2
+    assert "option -= not recognized" in output.getvalue()
+
+
+@pytest.mark.parametrize("v", ["i", "d"])
+def test_space_short_form_option(v: str) -> None:
+    """Regression test for https://github.com/pylint-dev/pylint/issues/9343"""
+    output = StringIO()
+    with redirect_stdout(output), pytest.raises(SystemExit) as ex:
+        similar.Run([f"-{v} 2", SIMILAR1, SIMILAR2])
+    assert ex.value.code == 2
+    assert "option -  not recognized" in output.getvalue()
+
+
+def test_bad_short_form_option() -> None:
+    """Regression test for https://github.com/pylint-dev/pylint/issues/9343"""
+    output = StringIO()
+    with redirect_stdout(output), pytest.raises(SystemExit) as ex:
+        similar.Run(["-j=0", SIMILAR1, SIMILAR2])
+    assert ex.value.code == 2
+    assert "option -j not recognized" in output.getvalue()