diff --git a/meshmode/mesh/processing.py b/meshmode/mesh/processing.py
index 5020364f..487174af 100644
--- a/meshmode/mesh/processing.py
+++ b/meshmode/mesh/processing.py
@@ -624,7 +624,8 @@ def unpack_single(ary: np.ndarray | None) -> np.ndarray:
 
     from pymbolic.geometric_algebra import MultiVector
 
-    mvs = [MultiVector(vec) for vec in spanning_object_array]
+    mvs: list[MultiVector[np.floating]] = (
+        [MultiVector(vec) for vec in spanning_object_array])
 
     from operator import xor
     outer_prod = -reduce(xor, mvs)      # pylint: disable=invalid-unary-operand-type