diff --git a/crossenv/__init__.py b/crossenv/__init__.py
index b1119f1..eab8f5f 100644
--- a/crossenv/__init__.py
+++ b/crossenv/__init__.py
@@ -464,15 +464,11 @@ def run_compiler(arg):
                 )
 
     def _split_apple_os_version(self, value):
-        # Split the Apple OS version from the OS name prefix.
-        if value.startswith("ios"):
-            offset = 3
-        elif value.startswith("tvos"):
-            offset = 4
-        elif value.startswith("watchos"):
-            offset = 7
-        else:
-            raise ValueError("Unknown Apple compiler triple.")
+        # Split the Apple OS version from the OS name prefix (e.g. ios13.0 ->
+        # ios, 13.0). No Apple OS name contains a digit, so the version starts
+        # at the first one. On macOS the version is the Darwin kernel version
+        # (e.g. darwin23.4.0), not the macOS version.
+        offset = next((i for i, c in enumerate(value) if c.isdigit()), len(value))
         return value[:offset], value[offset:]
 
     def _clean_triple(self, triple):
diff --git a/tests/test_triples.py b/tests/test_triples.py
new file mode 100644
index 0000000..1f8f170
--- /dev/null
+++ b/tests/test_triples.py
@@ -0,0 +1,59 @@
+#################################################
+# Compiler triple parsing (no crossenv required)
+#################################################
+
+import pytest
+
+from crossenv import CrossEnvBuilder
+
+
+@pytest.fixture
+def builder():
+    # These helpers only parse strings, so skip __init__ and its environment
+    # checks. They run on any platform.
+    return CrossEnvBuilder.__new__(CrossEnvBuilder)
+
+
+def test_split_apple_os_version(builder):
+    expected = {
+        "ios13.0": ("ios", "13.0"),
+        "ios": ("ios", ""),
+        "tvos17.0": ("tvos", "17.0"),
+        "tvos": ("tvos", ""),
+        "watchos10.0": ("watchos", "10.0"),
+        "watchos": ("watchos", ""),
+        "darwin23.4.0": ("darwin", "23.4.0"),
+        "darwin": ("darwin", ""),
+        # Previously rejected as unknown
+        "macos14.0": ("macos", "14.0"),
+        "macosx14.0": ("macosx", "14.0"),
+        "xros1.0": ("xros", "1.0"),
+    }
+    actual = {value: builder._split_apple_os_version(value) for value in expected}
+    assert actual == expected
+
+
+def test_clean_triple(builder):
+    expected = {
+        # Apple: arm64 -> aarch64, OS version removed. The clang -dumpmachine
+        # and HOST_GNU_TYPE forms must clean to the same value.
+        "arm64-apple-ios13.0": ["aarch64", "apple", "ios"],
+        "aarch64-apple-ios": ["aarch64", "apple", "ios"],
+        "arm64-apple-tvos17.0": ["aarch64", "apple", "tvos"],
+        "arm64-apple-watchos10.0": ["aarch64", "apple", "watchos"],
+        "arm64-apple-darwin23.4.0": ["aarch64", "apple", "darwin"],
+        "aarch64-apple-darwin": ["aarch64", "apple", "darwin"],
+        "x86_64-apple-darwin23.4.0": ["x86_64", "apple", "darwin"],
+        # Apple simulator: 4 parts, not compared
+        "arm64-apple-ios13.0-simulator": None,
+        # Non-Apple: vendor dropped from 4-part triples
+        "x86_64-linux-gnu": ["x86_64", "linux", "gnu"],
+        "x86_64-pc-linux-gnu": ["x86_64", "linux", "gnu"],
+        "aarch64-unknown-linux-gnu": ["aarch64", "linux", "gnu"],
+        # Other forms
+        "x86_64": None,
+        "aarch64-linux": None,
+        "a-b-c-d-e": None,
+    }
+    actual = {triple: builder._clean_triple(triple) for triple in expected}
+    assert actual == expected