diff --git a/devito/ir/clusters/cluster.py b/devito/ir/clusters/cluster.py
index 87044cbb886..887793e8e7e 100644
--- a/devito/ir/clusters/cluster.py
+++ b/devito/ir/clusters/cluster.py
@@ -13,7 +13,7 @@
 from devito.mpi.halo_scheme import HaloScheme, HaloTouch
 from devito.symbolics import estimate_cost
 from devito.tools import as_tuple, flatten, frozendict, infer_dtype
-from devito.types import Fence, WeakFence, CriticalRegion
+from devito.types import WeakFence, CriticalRegion
 
 __all__ = ["Cluster", "ClusterGroup"]
 
diff --git a/devito/ir/support/basic.py b/devito/ir/support/basic.py
index e218482f4e8..6c13a3f006e 100644
--- a/devito/ir/support/basic.py
+++ b/devito/ir/support/basic.py
@@ -24,7 +24,7 @@ class IndexMode(Tag):
 REGULAR = IndexMode('regular')
 IRREGULAR = IndexMode('irregular')
 
-# Symbols to create mock data depdendencies
+# Symbols to create mock data depdendencies
 mocksym0 = Symbol(name='__⋈_0__')
 mocksym1 = Symbol(name='__⋈_1__')
 
diff --git a/devito/passes/clusters/utils.py b/devito/passes/clusters/utils.py
index ef5a91b5597..abb4cec264d 100644
--- a/devito/passes/clusters/utils.py
+++ b/devito/passes/clusters/utils.py
@@ -1,5 +1,4 @@
 from collections import defaultdict
-from itertools import groupby
 
 from devito.ir import Cluster
 from devito.symbolics import uxreplace