diff --git a/lib/matplotlib/tri/triinterpolate.py b/lib/matplotlib/tri/triinterpolate.py
index 47a02b6cc820..998c01881208 100644
--- a/lib/matplotlib/tri/triinterpolate.py
+++ b/lib/matplotlib/tri/triinterpolate.py
@@ -462,9 +462,9 @@ def _interpolate_single_key(self, return_key, tri_index, x, y):
             dzdx = self._ReferenceElement.get_function_derivatives(
                 alpha, J, ecc, dof)
             if return_key == 'dzdx':
-                return dzdx[:, 0]
+                return dzdx[:, 0, 0]
             else:
-                return dzdx[:, 1]
+                return dzdx[:, 1, 0]
         else:
             raise ValueError("Invalid return_key: " + return_key)
 
diff --git a/lib/matplotlib/tri/trirefine.py b/lib/matplotlib/tri/trirefine.py
index 70a1166e736f..ae2f257a1f5e 100644
--- a/lib/matplotlib/tri/trirefine.py
+++ b/lib/matplotlib/tri/trirefine.py
@@ -117,7 +117,8 @@ def refine_triangulation(self, return_tri_index=False, subdiv=3):
             found_index = - np.ones(refi_npts, dtype=np.int32)
             tri_mask = self._triangulation.mask
             if tri_mask is None:
-                found_index[refi_triangles] = np.repeat(ancestors, 3)
+                found_index[refi_triangles] = np.repeat(ancestors,
+                                                        3).reshape(-1, 3)
             else:
                 # There is a subtlety here: we want to avoid whenever possible
                 # that refined points container is a masked triangle (which
@@ -126,9 +127,11 @@ def refine_triangulation(self, return_tri_index=False, subdiv=3):
                 # then overwrite it with unmasked ancestor numbers.
                 ancestor_mask = tri_mask[ancestors]
                 found_index[refi_triangles[ancestor_mask, :]
-                            ] = np.repeat(ancestors[ancestor_mask], 3)
+                            ] = np.repeat(ancestors[ancestor_mask],
+                                          3).reshape(-1, 3)
                 found_index[refi_triangles[~ancestor_mask, :]
-                            ] = np.repeat(ancestors[~ancestor_mask], 3)
+                            ] = np.repeat(ancestors[~ancestor_mask],
+                                          3).reshape(-1, 3)
             return refi_triangulation, found_index
         else:
             return refi_triangulation