diff --git a/pyproject.toml b/pyproject.toml
index 725b130..30dde20 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,7 +19,7 @@ classifiers = [
     "Topic :: Scientific/Engineering :: GIS",
     "Typing :: Typed",
 ]
-version = "0.2.1"
+version = "0.3.0"
 dependencies = ["pydantic>=2.3,<3"]
 
 [project.optional-dependencies]
diff --git a/src/covjson_pydantic/domain.py b/src/covjson_pydantic/domain.py
index 61dfdfb..af581c6 100644
--- a/src/covjson_pydantic/domain.py
+++ b/src/covjson_pydantic/domain.py
@@ -56,9 +56,9 @@ class DomainType(str, Enum):
 
 
 class Axes(CovJsonBaseModel):
-    x: Optional[Union[ValuesAxis[float], CompactAxis]] = None
-    y: Optional[Union[ValuesAxis[float], CompactAxis]] = None
-    z: Optional[Union[ValuesAxis[float], CompactAxis]] = None
+    x: Optional[Union[ValuesAxis[float], ValuesAxis[str], CompactAxis]] = None
+    y: Optional[Union[ValuesAxis[float], ValuesAxis[str], CompactAxis]] = None
+    z: Optional[Union[ValuesAxis[float], ValuesAxis[str], CompactAxis]] = None
     t: Optional[ValuesAxis[AwareDatetime]] = None
     composite: Optional[ValuesAxis[Tuple]] = None
 
diff --git a/tests/test_coverage.py b/tests/test_coverage.py
index e21ad75..4c678e6 100644
--- a/tests/test_coverage.py
+++ b/tests/test_coverage.py
@@ -16,6 +16,7 @@
 
 happy_cases = [
     ("spec-axes.json", Axes),
+    ("str-axes.json", Axes),
     ("coverage-json.json", Coverage),
     ("doc-example-coverage.json", Coverage),
     ("spec-vertical-profile-coverage.json", Coverage),
@@ -60,6 +61,8 @@ def test_happy_cases(file_name, object_type):
         + "domain must contain a single value.",
     ),
     ("point-series-domain-no-t.json", Domain, r"A 'PointSeries' must have a 't'-axis."),
+    ("mixed-type-axes.json", Axes, r"Input should be a valid number"),
+    ("mixed-type-axes-2.json", Axes, r"Input should be a valid string"),
 ]
 
 
diff --git a/tests/test_data/mixed-type-axes-2.json b/tests/test_data/mixed-type-axes-2.json
new file mode 100644
index 0000000..538c6b9
--- /dev/null
+++ b/tests/test_data/mixed-type-axes-2.json
@@ -0,0 +1,8 @@
+{
+    "x": {
+        "values": [
+            "foo",
+            42.0
+        ]
+    }
+}
diff --git a/tests/test_data/mixed-type-axes.json b/tests/test_data/mixed-type-axes.json
new file mode 100644
index 0000000..2546157
--- /dev/null
+++ b/tests/test_data/mixed-type-axes.json
@@ -0,0 +1,8 @@
+{
+    "x": {
+        "values": [
+            42.0,
+            "foo"
+        ]
+    }
+}
diff --git a/tests/test_data/str-axes.json b/tests/test_data/str-axes.json
new file mode 100644
index 0000000..525f7ce
--- /dev/null
+++ b/tests/test_data/str-axes.json
@@ -0,0 +1,8 @@
+{
+    "x": {
+        "values": [
+            "foo",
+            "bar"
+        ]
+    }
+}