diff --git a/sstables/compaction.cc b/sstables/compaction.cc
index 7a6387391e..f4de750745 100644
--- a/sstables/compaction.cc
+++ b/sstables/compaction.cc
@@ -163,6 +163,64 @@ static std::vector<shared_sstable> get_uncompacting_sstables(column_family& cf,
 
 class compaction;
 
+class compaction_write_monitor final : public sstables::write_monitor, public backlog_write_progress_manager {
+    sstables::shared_sstable _sst;
+    column_family& _cf;
+    const sstables::writer_offset_tracker* _tracker = nullptr;
+    uint64_t _progress_seen = 0;
+    api::timestamp_type _maximum_timestamp;
+    unsigned _sstable_level;
+public:
+    compaction_write_monitor(sstables::shared_sstable sst, column_family& cf, api::timestamp_type max_timestamp, unsigned sstable_level)
+        : _sst(sst)
+        , _cf(cf)
+        , _maximum_timestamp(max_timestamp)
+        , _sstable_level(sstable_level)
+    {}
+
+    ~compaction_write_monitor() {
+        if (_sst) {
+            _cf.get_compaction_strategy().get_backlog_tracker().revert_charges(_sst);
+        }
+    }
+
+    virtual void on_write_started(const sstables::writer_offset_tracker& tracker) override {
+        _tracker = &tracker;
+        _cf.get_compaction_strategy().get_backlog_tracker().register_partially_written_sstable(_sst, *this);
+    }
+
+    virtual void on_data_write_completed() override {
+        if (_tracker) {
+            _progress_seen = _tracker->offset;
+            _tracker = nullptr;
+        }
+    }
+
+    virtual void write_failed() override {
+        _cf.get_compaction_strategy().get_backlog_tracker().revert_charges(std::move(_sst));
+    }
+
+    virtual uint64_t written() const {
+        if (_tracker) {
+            return _tracker->offset;
+        }
+        return _progress_seen;
+    }
+
+    void add_sstable() {
+        _cf.get_compaction_strategy().get_backlog_tracker().add_sstable(_sst);
+        _sst = {};
+    }
+
+    api::timestamp_type maximum_timestamp() const override {
+        return _maximum_timestamp;
+    }
+
+    unsigned level() const override {
+        return _sstable_level;
+    }
+};
+
 struct compaction_writer {
     sstable_writer writer;
     shared_sstable sst;
@@ -273,64 +331,6 @@ private:
      std::deque<compaction_read_monitor> _generated_monitors;
 };
 
-class compaction_write_monitor final : public sstables::write_monitor, public backlog_write_progress_manager {
-    sstables::shared_sstable _sst;
-    column_family& _cf;
-    const sstables::writer_offset_tracker* _tracker = nullptr;
-    uint64_t _progress_seen = 0;
-    api::timestamp_type _maximum_timestamp;
-    unsigned _sstable_level;
-public:
-    compaction_write_monitor(sstables::shared_sstable sst, column_family& cf, api::timestamp_type max_timestamp, unsigned sstable_level)
-        : _sst(sst)
-        , _cf(cf)
-        , _maximum_timestamp(max_timestamp)
-        , _sstable_level(sstable_level)
-    {}
-
-    ~compaction_write_monitor() {
-        if (_sst) {
-            _cf.get_compaction_strategy().get_backlog_tracker().revert_charges(_sst);
-        }
-    }
-
-    virtual void on_write_started(const sstables::writer_offset_tracker& tracker) override {
-        _tracker = &tracker;
-        _cf.get_compaction_strategy().get_backlog_tracker().register_partially_written_sstable(_sst, *this);
-    }
-
-    virtual void on_data_write_completed() override {
-        if (_tracker) {
-            _progress_seen = _tracker->offset;
-            _tracker = nullptr;
-        }
-    }
-
-    virtual void write_failed() override {
-        _cf.get_compaction_strategy().get_backlog_tracker().revert_charges(std::move(_sst));
-    }
-
-    virtual uint64_t written() const {
-        if (_tracker) {
-            return _tracker->offset;
-        }
-        return _progress_seen;
-    }
-
-    void add_sstable() {
-        _cf.get_compaction_strategy().get_backlog_tracker().add_sstable(_sst);
-        _sst = {};
-    }
-
-    api::timestamp_type maximum_timestamp() const override {
-        return _maximum_timestamp;
-    }
-
-    unsigned level() const override {
-        return _sstable_level;
-    }
-};
-
 // Writes a temporary sstable run containing only garbage collected data.
 // Whenever regular compaction writer seals a new sstable, this writer will flush a new sstable as well,
 // right before there's an attempt to release exhausted sstables earlier.