diff --git a/src/openmcmc/parameter.py b/src/openmcmc/parameter.py
index 0c692a6..3ca5c7c 100644
--- a/src/openmcmc/parameter.py
+++ b/src/openmcmc/parameter.py
@@ -533,4 +533,6 @@ def precision_unscaled(self, state: dict, element_index: int) -> np.ndarray:
             (np.ndarray): unscaled precision matrix
 
         """
-        return sparse.diags(diagonals=self.get_element_match(state, element_index).flatten(), offsets=0, format="csc")
+        return sparse.diags(
+            diagonals=self.get_element_match(state, element_index).flatten(), offsets=0, format="csc", dtype=np.float64
+        )