diff --git a/lib/iris/tests/results/netcdf/int64_data_netcdf3.cml b/lib/iris/tests/results/netcdf/int64_data_netcdf3.cml
index f1e9a3bb2c..93da2db83d 100644
--- a/lib/iris/tests/results/netcdf/int64_data_netcdf3.cml
+++ b/lib/iris/tests/results/netcdf/int64_data_netcdf3.cml
@@ -1,6 +1,6 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
-  <cube core-dtype="float64" dtype="int32" standard_name="surface_temperature" units="K" var_name="temp">
+  <cube core-dtype="int32" dtype="int32" standard_name="surface_temperature" units="K" var_name="temp">
     <attributes>
       <attribute name="Conventions" value="CF-1.5"/>
     </attributes>
diff --git a/lib/iris/tests/results/netcdf/netcdf_units_0.cml b/lib/iris/tests/results/netcdf/netcdf_units_0.cml
index 363577c6f1..18a561b2e9 100644
--- a/lib/iris/tests/results/netcdf/netcdf_units_0.cml
+++ b/lib/iris/tests/results/netcdf/netcdf_units_0.cml
@@ -1,6 +1,6 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
-  <cube core-dtype="float64" dtype="int32" standard_name="air_temperature" units="kelvin" var_name="cube_0">
+  <cube core-dtype="int32" dtype="int32" standard_name="air_temperature" units="kelvin" var_name="cube_0">
     <coords>
       <coord>
         <dimCoord id="f1596e20" points="[100]" shape="(1,)" standard_name="height" units="Unit('meters')" value_type="int32" var_name="height"/>
diff --git a/lib/iris/tests/results/netcdf/uint32_data_netcdf3.cml b/lib/iris/tests/results/netcdf/uint32_data_netcdf3.cml
index f1e9a3bb2c..05ac5ec7a8 100644
--- a/lib/iris/tests/results/netcdf/uint32_data_netcdf3.cml
+++ b/lib/iris/tests/results/netcdf/uint32_data_netcdf3.cml
@@ -1,6 +1,6 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
-  <cube core-dtype="float64" dtype="int32" standard_name="surface_temperature" units="K" var_name="temp">
+  <cube core-dtype="int64" dtype="int32" standard_name="surface_temperature" units="K" var_name="temp">
     <attributes>
       <attribute name="Conventions" value="CF-1.5"/>
     </attributes>
diff --git a/lib/iris/tests/test_pickling.py b/lib/iris/tests/test_pickling.py
index 097fabdf4e..b94ddfd947 100644
--- a/lib/iris/tests/test_pickling.py
+++ b/lib/iris/tests/test_pickling.py
@@ -55,9 +55,7 @@ def pickle_then_unpickle(self, obj):
     def _real_data(cube):
         # Get the concrete data of the cube for performing data values
         # comparison checks.
-        return as_concrete_data(cube.core_data(),
-                                nans_replacement=cube.fill_value,
-                                result_dtype=cube.dtype)
+        return as_concrete_data(cube.core_data())
 
     def assertCubeData(self, cube1, cube2):
         self.assertArrayEqual(self._real_data(cube1), self._real_data(cube2))
diff --git a/lib/iris/tests/unit/analysis/test_MEAN.py b/lib/iris/tests/unit/analysis/test_MEAN.py
index 6460137419..3d40e7eb5e 100644
--- a/lib/iris/tests/unit/analysis/test_MEAN.py
+++ b/lib/iris/tests/unit/analysis/test_MEAN.py
@@ -43,13 +43,13 @@ def setUp(self):
 
     def test_mdtol_default(self):
         agg = MEAN.lazy_aggregate(self.array, axis=self.axis)
-        masked_result = as_concrete_data(agg, nans_replacement=ma.masked)
+        masked_result = as_concrete_data(agg)
         self.assertMaskedArrayAlmostEqual(masked_result,
                                           self.expected_masked)
 
     def test_mdtol_below(self):
         agg = MEAN.lazy_aggregate(self.array, axis=self.axis, mdtol=0.3)
-        masked_result = as_concrete_data(agg, nans_replacement=ma.masked)
+        masked_result = as_concrete_data(agg)
         expected_masked = self.expected_masked
         expected_masked.mask = [False, True, True, True]
         self.assertMaskedArrayAlmostEqual(masked_result,
@@ -57,7 +57,7 @@ def test_mdtol_below(self):
 
     def test_mdtol_above(self):
         agg = MEAN.lazy_aggregate(self.array, axis=self.axis, mdtol=0.4)
-        masked_result = as_concrete_data(agg, nans_replacement=ma.masked)
+        masked_result = as_concrete_data(agg)
         self.assertMaskedArrayAlmostEqual(masked_result,
                                           self.expected_masked)
 
@@ -66,7 +66,7 @@ def test_multi_axis(self):
         collapse_axes = (0, 2)
         lazy_data = as_lazy_data(data)
         agg = MEAN.lazy_aggregate(lazy_data, axis=collapse_axes)
-        result = as_concrete_data(agg, nans_replacement=ma.masked)
+        result = as_concrete_data(agg)
         expected = np.mean(data, axis=collapse_axes)
         self.assertArrayAllClose(result, expected)