diff --git a/src/myxa/models.py b/src/myxa/models.py
index 5e330cc..e3e0a42 100644
--- a/src/myxa/models.py
+++ b/src/myxa/models.py
@@ -1,9 +1,12 @@
 import logging
+import re
 from enum import StrEnum
 from typing import Literal, Optional, Self, Union
 
 from pydantic import BaseModel, Field
 
+from myxa.errors import UserError
+
 logger = logging.getLogger(__name__)
 
 
@@ -58,6 +61,9 @@ def to_str(self) -> str:
 
     @classmethod
     def from_str(cls, s: str) -> Self:
+        if not re.match(r"\d+\.\d+", s):
+            msg = f"Invalid version string: {s}"
+            raise UserError(msg)
         parts = s.split(".")
         major = int(parts[0])
         minor = int(parts[1])
diff --git a/tests/test_models.py b/tests/test_models.py
new file mode 100644
index 0000000..4b7ef25
--- /dev/null
+++ b/tests/test_models.py
@@ -0,0 +1,10 @@
+import pytest
+
+from myxa.errors import UserError
+from myxa.models import Version
+
+
+class TestModels:
+    def test_version_invalid_from_str_raises_user_error(self) -> None:
+        with pytest.raises(UserError, match="Invalid version string: 100"):
+            Version.from_str("100")