diff --git a/tests/test_domain.py b/tests/test_domain.py
index 9e655041..c26b2bbf 100644
--- a/tests/test_domain.py
+++ b/tests/test_domain.py
@@ -173,20 +173,20 @@ def test_returns_failed_validation_on_domain_beyond_rfc_limits(value: str):
     "value",
     [
         # IDNA 2003 maps these to "example.com"; see `_relies_on_idna_mapping`
-        "example.ｃｏｍ",  # fullwidth letters
-        "ｅｘａｍｐｌｅ.com",
-        "example.ⅽom",  # small roman numeral one hundred
-        "Kelvin.com",  # Kelvin sign
-        "ſhop.com",  # long s
+        "example.\uff43\uff4f\uff4d",  # fullwidth letters
+        "\uff45\uff58\uff41\uff4d\uff50\uff4c\uff45.com",
+        "example.\u217dom",  # small roman numeral one hundred
+        "\u212aelvin.com",  # Kelvin sign
+        "\u017fhop.com",  # long s
         "example。com",  # ideographic full stop
-        "example．com",  # fullwidth full stop
-        "example｡com",  # halfwidth ideographic full stop
-        "exam­ple.com",  # soft hyphen
-        "example.co​m",  # zero width space
-        "exa‍mple.com",  # zero width joiner
-        "exam️ple.com",  # variation selector
-        "examp⁠le.com",  # word joiner
-        "example.com",  # zero width no-break space
+        "example\uff0ecom",  # fullwidth full stop
+        "example\uff61com",  # halfwidth ideographic full stop
+        "exam\u00adple.com",  # soft hyphen
+        "example.co\u200bm",  # zero width space
+        "exa\u200dmple.com",  # zero width joiner
+        "exam\ufe0fple.com",  # variation selector
+        "examp\u2060le.com",  # word joiner
+        "\ufeffexample.com",  # zero width no-break space
         "exämple.com".replace("ä", "ä"),  # not NFC
     ],
 )
diff --git a/tests/test_email.py b/tests/test_email.py
index f3066c88..9b82eb46 100644
--- a/tests/test_email.py
+++ b/tests/test_email.py
@@ -68,7 +68,7 @@ def test_rejects_newline_after_local_part(local_part: str):
     assert isinstance(email(f"{local_part}\n@example.com"), ValidationError)
 
 
-@pytest.mark.parametrize("domain_part", ["example.ｃｏｍ", "exam­ple.com"])
+@pytest.mark.parametrize("domain_part", ["example.\uff43\uff4f\uff4d", "exam\u00adple.com"])
 def test_returns_failed_validation_on_idna_mapped_lookalike_domain(domain_part: str):
     """Test returns failed validation on email domains that only IDNA 2003 mapping makes valid."""
     assert isinstance(email(f"user@{domain_part}"), ValidationError)
diff --git a/tests/test_hostname.py b/tests/test_hostname.py
index 97671267..5855649c 100644
--- a/tests/test_hostname.py
+++ b/tests/test_hostname.py
@@ -127,13 +127,15 @@ def test_rejects_trailing_newline_in_hostnames_and_ports(value: str):
     assert isinstance(hostname(value), ValidationError)
 
 
-@pytest.mark.parametrize("value", ["ſerver", "Kelvin", "ıntranet", "İntranet:8080"])
+@pytest.mark.parametrize(
+    "value", ["\u017ferver", "\u212aelvin", "\u0131ntranet", "\u0130ntranet:8080"]
+)
 def test_returns_failed_validation_on_non_ascii_simple_hostname(value: str):
     """Test returns failed validation on non-ASCII case equivalents in simple hostnames."""
     assert isinstance(hostname(value), ValidationError)
 
 
-@pytest.mark.parametrize("value", ["example.ｃｏｍ", "exam­ple.com:443"])
+@pytest.mark.parametrize("value", ["example.\uff43\uff4f\uff4d", "exam\u00adple.com:443"])
 def test_returns_failed_validation_on_idna_mapped_lookalike_hostname(value: str):
     """Test returns failed validation on hostnames that only IDNA 2003 mapping makes valid."""
     assert isinstance(hostname(value), ValidationError)
diff --git a/tests/test_url.py b/tests/test_url.py
index 2cfded8b..af22edb3 100644
--- a/tests/test_url.py
+++ b/tests/test_url.py
@@ -261,7 +261,7 @@ def test_url_accepts_percent_encoded_controls(encoded: str, template: str):
 
 @pytest.mark.parametrize(
     "value",
-    ["https://example.ｃｏｍ/", "https://exam­ple.com/", "http://ſerver/"],
+    ["https://example.\uff43\uff4f\uff4d/", "https://exam\u00adple.com/", "http://\u017ferver/"],
 )
 def test_returns_failed_validation_on_idna_mapped_lookalike_url(value: str):
     """Test returns failed validation on url hosts that only IDNA 2003 mapping makes valid."""