diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e40cdc9..02d971c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -47,7 +47,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-latest]
+        os: [ubuntu-latest, macos-latest, windows-latest]
         env: ["py310", "py311", "py312"]
     steps:
       - name: Checkout branch
diff --git a/metalearners/_utils.py b/metalearners/_utils.py
index 2767d5a..a39c2c2 100644
--- a/metalearners/_utils.py
+++ b/metalearners/_utils.py
@@ -234,9 +234,10 @@ def convert_treatment(treatment: Vector) -> np.ndarray:
         new_treatment = treatment.to_numpy()
     if new_treatment.dtype == bool:
         return new_treatment.astype(int)
-    elif new_treatment.dtype == float and all(x.is_integer() for x in new_treatment):
+    if new_treatment.dtype == float and all(x.is_integer() for x in new_treatment):
         return new_treatment.astype(int)
-    elif new_treatment.dtype != int:
+
+    if not pd.api.types.is_integer_dtype(new_treatment):
         raise TypeError(
             "Treatment must be boolean, integer or float with integer values."
         )