diff --git a/meshmode/mesh/processing.py b/meshmode/mesh/processing.py
index d420c08d0fc88867e3a67488abd959486946eca3..664355e0f043089af35efbd1ed79b0fdec7e71d8 100644
--- a/meshmode/mesh/processing.py
+++ b/meshmode/mesh/processing.py
@@ -447,6 +447,8 @@ def map_mesh(mesh, f):  # noqa
     shape ``(ambient_dim, npoints)``."""
 
     vertices = f(mesh.vertices)
+    if not vertices.flags.c_contiguous:
+        vertices = np.copy(vertices, order="C")
 
     # {{{ assemble new groups list
 
@@ -454,6 +456,9 @@ def map_mesh(mesh, f):  # noqa
 
     for group in mesh.groups:
         mapped_nodes = f(group.nodes.reshape(mesh.ambient_dim, -1))
+        if not mapped_nodes.flags.c_contiguous:
+            mapped_nodes = np.copy(mapped_nodes, order="C")
+
         new_groups.append(group.copy(
             nodes=mapped_nodes.reshape(*group.nodes.shape)))
 
@@ -479,7 +484,7 @@ def affine_map(mesh, A=None, b=None):  # noqa
         b = np.zeros(A.shape[0])
 
     def f(x):
-        return np.einsum("ij,jv->iv", A, x) + b[:, np.newaxis]
+        return np.dot(A, x) + b.reshape(-1, 1)
 
     return map_mesh(mesh, f)