diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b68dc3fe4346d5a1c035700d5a9d17c94bf161b3..3f331f0cc2aa5b5d8def8df4b97f8e09526b25b7 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -15,15 +15,15 @@ Python 2.7 POCL:
     reports:
       junit: test/pytest.xml
 
-Python 3.6 Nvidia K40:
+Python 3 Nvidia K40:
   script:
-  - export PY_EXE=python3.6
+  - export PY_EXE=python3
   - export PYOPENCL_TEST=nvi:k40
   - export EXTRA_INSTALL="pybind11 numpy mako"
   - curl -L -O -k https://gitlab.tiker.net/inducer/ci-support/raw/master/build-and-test-py-project.sh
   - ". ./build-and-test-py-project.sh"
   tags:
-  - python3.6
+  - python3
   - nvidia-k40
   except:
   - tags
@@ -31,15 +31,15 @@ Python 3.6 Nvidia K40:
     reports:
       junit: test/pytest.xml
 
-Python 3.6 POCL:
+Python 3 POCL:
   script:
-  - export PY_EXE=python3.6
+  - export PY_EXE=python3
   - export PYOPENCL_TEST=portable
   - export EXTRA_INSTALL="pybind11 numpy mako mpi4py"
   - curl -L -O -k https://gitlab.tiker.net/inducer/ci-support/raw/master/build-and-test-py-project.sh
   - ". ./build-and-test-py-project.sh"
   tags:
-  - python3.6
+  - python3
   - pocl
   - mpi
   except:
@@ -48,15 +48,15 @@ Python 3.6 POCL:
     reports:
       junit: test/pytest.xml
 
-Python 3.7 POCL:
+Python 3 POCL:
   script:
-  - export PY_EXE=python3.7
+  - export PY_EXE=python3
   - export PYOPENCL_TEST=portable
   - export EXTRA_INSTALL="pybind11 numpy mako mpi4py"
   - curl -L -O -k https://gitlab.tiker.net/inducer/ci-support/raw/master/build-and-test-py-project.sh
   - ". ./build-and-test-py-project.sh"
   tags:
-  - python3.7
+  - python3
   - pocl
   - mpi
   except:
@@ -71,7 +71,7 @@ Documentation:
   - curl -L -O -k https://gitlab.tiker.net/inducer/ci-support/raw/master/build-docs.sh
   - ". ./build-docs.sh"
   tags:
-  - python3.5
+  - python3
   only:
   - master
 
@@ -80,6 +80,6 @@ Flake8:
   - curl -L -O -k https://gitlab.tiker.net/inducer/ci-support/raw/master/prepare-and-run-flake8.sh
   - ". ./prepare-and-run-flake8.sh meshmode test"
   tags:
-  - python3.5
+  - python3
   except:
   - tags
diff --git a/meshmode/mesh/io.py b/meshmode/mesh/io.py
index e4adf7ce50983c863d82da66edfbc405c9c68f23..49e816f84940d4f765703a8adc53ff327e3e69a8 100644
--- a/meshmode/mesh/io.py
+++ b/meshmode/mesh/io.py
@@ -375,6 +375,9 @@ def from_vertices_and_simplices(vertices, simplices, order=1, fix_orientation=Fa
     grp = make_group_from_vertices(vertices, simplices, order)
 
     if fix_orientation:
+        if grp.dim != vertices.shape[0]:
+            raise ValueError("can only fix orientation of volume meshes")
+
         from meshmode.mesh.processing import (
                 find_volume_mesh_element_group_orientation,
                 flip_simplex_element_group)
diff --git a/meshmode/mesh/processing.py b/meshmode/mesh/processing.py
index 2094c99bd9dbe0f0db29b2fe7253c8796eedc149..9cb71a1a501f2e79d94e9c09a7ef6847b5b621f7 100644
--- a/meshmode/mesh/processing.py
+++ b/meshmode/mesh/processing.py
@@ -289,6 +289,9 @@ def find_volume_mesh_element_group_orientation(vertices, grp):
     ambient_dim = spanning_vectors.shape[0]
     nspan_vectors = spanning_vectors.shape[-1]
 
+    if ambient_dim != grp.dim:
+        raise ValueError("can only find orientation of volume meshes")
+
     spanning_object_array = np.empty(
             (nspan_vectors, ambient_dim),
             dtype=np.object)