diff --git a/devito/passes/clusters/implicit.py b/devito/passes/clusters/implicit.py
index 6c1cab378a..100ba4842a 100644
--- a/devito/passes/clusters/implicit.py
+++ b/devito/passes/clusters/implicit.py
@@ -182,8 +182,9 @@ def callback(self, clusters, prefix):
             if dim not in edims or not edims.issubset(prefix.dimensions):
                 continue
 
-            found[d.msd].clusters.append(c)
-            found[d.msd].mapper = reduce(found[d.msd].mapper, mapper, edims, prefix)
+            found[d.functions].clusters.append(c)
+            found[d.functions].mapper = reduce(found[d.functions].mapper,
+                                               mapper, edims, prefix)
 
         # Turn the reduced mapper into a list of equations
         mapper = {}
diff --git a/devito/types/grid.py b/devito/types/grid.py
index ab767932fd..d49cf95ad7 100644
--- a/devito/types/grid.py
+++ b/devito/types/grid.py
@@ -783,12 +783,7 @@ def __subdomain_finalize__(self, grid, counter=0, **kwargs):
             # Check if shorthand notation has been provided:
             for j in range(2):
                 idx = 2*i + j
-                if isinstance(self._local_bounds[idx], int):
-                    sd_func.data[:, idx] = np.full((self._n_domains,),
-                                                   self._local_bounds[idx],
-                                                   dtype=np.int32)
-                else:
-                    sd_func.data[:, idx] = self._local_bounds[idx]
+                sd_func.data[:, idx] = self._local_bounds[idx]
 
             dname = '%si%d' % (d.name, counter)
             dimensions.append(MultiSubDimension(dname, d,
diff --git a/tests/test_subdomains.py b/tests/test_subdomains.py
index 432f13e230..5ee2076fd9 100644
--- a/tests/test_subdomains.py
+++ b/tests/test_subdomains.py
@@ -642,6 +642,15 @@ class Dummy(SubDomainSet):
         assert_structure(op, ['t,n0', 't,n0,xi20_blk0,yi20_blk0,x,y,z'],
                          't,n0,xi20_blk0,yi20_blk0,x,y,z')
 
+        xi, _, _ = dummy.dimensions
+        # Check that the correct number of thickness expressions are generated
+        sdsexprs = [i.expr for i in FindNodes(Expression).visit(op)
+                    if i.expr.rhs.is_Indexed
+                    and i.expr.rhs.function is xi.functions]
+        # The thickness expressions Eq(x_ltkn0, dummy[n0][0]), ...
+        # should be scheduled once per dimension
+        assert len(sdsexprs) == 6
+
     def test_sequential_implicit(self):
         """
         Make sure the implicit dimensions of the MultiSubDomain define a sequential