diff --git a/sstables/sstable_set.cc b/sstables/sstable_set.cc
index e96ed4a4b3..4e9b9f0d17 100644
--- a/sstables/sstable_set.cc
+++ b/sstables/sstable_set.cc
@@ -471,16 +471,27 @@ public:
     }
 };
 
+// The returned function uses the bloom filter to check whether the given sstable
+// may have a partition given by the ring position `pos`.
+//
+// Returning `false` means the sstable doesn't have such a partition.
+// Returning `true` means it may, i.e. we don't know whether or not it does.
+//
+// Assumes the given `pos` and `schema` are alive during the function's lifetime.
+static std::predicate<const sstable&> auto
+make_pk_filter(const dht::ring_position& pos, const schema& schema) {
+    return [&pos, key = key::from_partition_key(schema, *pos.key()), cmp = dht::ring_position_comparator(schema)] (const sstable& sst) {
+        return cmp(pos, sst.get_first_decorated_key()) >= 0 &&
+               cmp(pos, sst.get_last_decorated_key()) <= 0 &&
+               sst.filter_has_key(key);
+    };
+}
+
 // Filter out sstables for reader using bloom filter
 static std::vector<shared_sstable>
-filter_sstable_for_reader_by_pk(std::vector<shared_sstable>&& sstables, column_family& cf, const schema_ptr& schema,
-        const dht::ring_position& pos, const key& key) {
-    auto sstable_has_not_key = [&, cmp = dht::ring_position_comparator(*schema)] (const shared_sstable& sst) {
-        return cmp(pos, sst->get_first_decorated_key()) < 0 ||
-               cmp(pos, sst->get_last_decorated_key()) > 0 ||
-               !sst->filter_has_key(key);
-    };
-    sstables.erase(boost::remove_if(sstables, sstable_has_not_key), sstables.end());
+filter_sstable_for_reader_by_pk(std::vector<shared_sstable>&& sstables, const schema& schema, const dht::ring_position& pos) {
+    auto filter = [_filter = make_pk_filter(pos, schema)] (const shared_sstable& sst) { return !_filter(*sst); };
+    sstables.erase(boost::remove_if(sstables, filter), sstables.end());
     return sstables;
 }
 
@@ -531,9 +542,7 @@ sstable_set::create_single_key_sstable_reader(
         streamed_mutation::forwarding fwd,
         mutation_reader::forwarding fwd_mr) const
 {
-    auto& pk = pos.key();
-    auto key = key::from_partition_key(*schema, *pk);
-    auto selected_sstables = filter_sstable_for_reader_by_pk(select({pos}), *cf, schema, pos, key);
+    auto selected_sstables = filter_sstable_for_reader_by_pk(select({pos}), *schema, pos);
     auto num_sstables = selected_sstables.size();
     if (!num_sstables) {
         return make_empty_flat_reader(schema, permit);
@@ -556,7 +565,7 @@ sstable_set::create_single_key_sstable_reader(
     // all sstables actually containing the partition were filtered.
     auto num_readers = readers.size();
     if (num_readers != num_sstables) {
-        readers.push_back(flat_mutation_reader_from_mutations(permit, {mutation(schema, *pk)}, slice, fwd));
+        readers.push_back(flat_mutation_reader_from_mutations(permit, {mutation(schema, *pos.key())}, slice, fwd));
     }
     sstable_histogram.add(num_readers);
     return make_combined_reader(schema, std::move(permit), std::move(readers), fwd, fwd_mr);