diff --git a/src/psyclone/psyGen.py b/src/psyclone/psyGen.py
index b886cb2910..921fe6e907 100644
--- a/src/psyclone/psyGen.py
+++ b/src/psyclone/psyGen.py
@@ -1379,13 +1379,13 @@ def get_kernel_schedule(self):
                   kernel code.
         :rtype: tuple[:py:class:`psyclone.psyir.symbols.Symbol`,
                       list[:py:class:`psyclone.psyir.nodes.KernelSchedule`]]
+
+        :raises NotImplementedError: must be overridden in sub-class.
+
         '''
-        from psyclone.psyir.frontend.fparser2 import Fparser2Reader
-        if self._kern_schedule is None:
-            astp = Fparser2Reader()
-            self._kern_schedule = [astp.generate_schedule(self.name, self.ast)]
-            # TODO: Validate kernel with metadata (issue #288).
-        return None, self._kern_schedule
+        raise NotImplementedError(
+            f"get_kernel_schedule() must be overridden in class "
+            f"{self.__class__}")
 
     @property
     def opencl_options(self):
diff --git a/src/psyclone/tests/domain/gocean/transformations/globalstoargs_test.py b/src/psyclone/tests/domain/gocean/transformations/globalstoargs_test.py
index 560bc3a498..278eaac1ab 100644
--- a/src/psyclone/tests/domain/gocean/transformations/globalstoargs_test.py
+++ b/src/psyclone/tests/domain/gocean/transformations/globalstoargs_test.py
@@ -34,15 +34,16 @@
 # Authors: A. R. Porter and S. Siso, STFC Daresbury Lab
 # Modified by R. W. Ford, STFC Daresbury Lab
 
-''' Tests the KernelImportsToArguments Transformation for the GOcean
-1.0 API.'''
+''' Tests the KernelImportsToArguments Transformation for the GOcean API.'''
 
 import os
 import pytest
+from psyclone.gocean1p0 import GOInvokeSchedule
 from psyclone.parse.algorithm import parse
 from psyclone.psyGen import PSyFactory, InvokeSchedule
 from psyclone.psyir.symbols import DataSymbol, REAL_TYPE, INTEGER_TYPE, \
     CHARACTER_TYPE, Symbol
+from psyclone.tests.utilities import get_invoke
 from psyclone.transformations import KernelImportsToArguments, \
     TransformationError
 
@@ -106,6 +107,26 @@ def test_kernelimportstoargumentstrans_no_wildcard_import():
             "container 'model_mod'" in str(err.value))
 
 
+def test_kernelimportstoargumentstrans_no_polymorphic(monkeypatch):
+    '''
+    Check that the transformation rejects polymorphic kernels.
+
+    '''
+    trans = KernelImportsToArguments()
+    _, invoke = get_invoke("26.8_mixed_precision_args.f90", api="lfric", idx=0)
+    kernel = invoke.schedule.coded_kernels()[0]
+    invsched = kernel.ancestor(InvokeSchedule)
+    # Currently this transformation will only work for the GOcean API so
+    # monkeypatch the class of the parent InvokeSchedule.
+    monkeypatch.setattr(invsched, "__class__", GOInvokeSchedule)
+    with pytest.raises(TransformationError) as err:
+        trans.validate(kernel)
+    assert ("KernelImportsToArguments transformation does not support "
+            "polymorphic kernels but found the following implementations for "
+            "kernel 'mixed_code': ['mixed_code_32', 'mixed_code_64']"
+            in str(err.value))
+
+
 @pytest.mark.xfail(reason="Transformation does not set modified property "
                    "of kernel - #663")
 @pytest.mark.usefixtures("kernel_outputdir")
diff --git a/src/psyclone/tests/psyGen_test.py b/src/psyclone/tests/psyGen_test.py
index a4b84ba0e8..09fd60d0d9 100644
--- a/src/psyclone/tests/psyGen_test.py
+++ b/src/psyclone/tests/psyGen_test.py
@@ -703,6 +703,23 @@ def test_kern_children_validation():
             "is a LeafNode and doesn't accept children.") in str(excinfo.value)
 
 
+def test_codedkern_get_kernel_schedule(monkeypatch):
+    '''
+    Check that CodedKern.get_kernel_schedule() raises a NotImplementedError
+    (as it must be implemented by sub-classes).
+
+    '''
+    ast = fpapi.parse(FAKE_KERNEL_METADATA, ignore_comments=False)
+    metadata = LFRicKernMetadata(ast)
+    kern = LFRicKern()
+    kern.load_meta(metadata)
+    monkeypatch.setattr(kern, "__class__", CodedKern)
+    with pytest.raises(NotImplementedError) as err:
+        kern.get_kernel_schedule()
+    assert ("get_kernel_schedule() must be overridden in class "
+            in str(err.value))
+
+
 def test_inlinedkern_children_validation():
     '''Test that children added to InlinedKern are validated. An InlinedKern
     must have one child that is a Schedule (which is created by its