diff --git a/loopy/transform/diff.py b/loopy/transform/diff.py
index a292cb66623e68f60f311b03f8ea7e0c3689b11b..d4dcb3701f4f23a5b1c66b1559bf6c4879425902 100644
--- a/loopy/transform/diff.py
+++ b/loopy/transform/diff.py
@@ -370,7 +370,7 @@ def diff_kernel(knl, diff_outputs, by, diff_iname_prefix="diff_i",
         *diff_context.by_name*, or *None* if no dependency exists.
     """
 
-    from loopy.preprocess import apply_single_writer_depencency_heuristic
+    from loopy.kernel.creation import apply_single_writer_depencency_heuristic
     knl = apply_single_writer_depencency_heuristic(knl, warn_if_used=True)
 
     if isinstance(diff_outputs, str):
diff --git a/loopy/transform/subst.py b/loopy/transform/subst.py
index 5f0db65d67d60db90d2dde9a77b7df7e6edfd396..b2b76ae9f3a92d93feca2dc9b31591f215b9341e 100644
--- a/loopy/transform/subst.py
+++ b/loopy/transform/subst.py
@@ -311,7 +311,7 @@ def assignment_to_subst(kernel, lhs_name, extra_arguments=(), within=None,
     # {{{ establish the relevant definition of lhs_name for each usage site
 
     dep_kernel = expand_subst(kernel)
-    from loopy.preprocess import apply_single_writer_depencency_heuristic
+    from loopy.kernel.creation import apply_single_writer_depencency_heuristic
     dep_kernel = apply_single_writer_depencency_heuristic(dep_kernel)
 
     id_to_insn = dep_kernel.id_to_insn