diff --git a/CHANGES.txt b/CHANGES.txt
index 7d4b7a9fcf..9b4f8c3e8a 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,4 +1,5 @@
 3.0.22:
+ * Remove broken 'defrag-on-read' optimization (CASSANDRA-15432)
  * Check for endpoint collision with hibernating nodes (CASSANDRA-14599)
  * Operational improvements and hardening for replica filtering protection (CASSANDRA-15907)
  * stop_paranoid disk failure policy is ignored on CorruptSSTableException after node is up (CASSANDRA-15191)
diff --git a/src/java/org/apache/cassandra/db/SinglePartitionReadCommand.java b/src/java/org/apache/cassandra/db/SinglePartitionReadCommand.java
index 841c3b9f99..ca4e8e3758 100644
--- a/src/java/org/apache/cassandra/db/SinglePartitionReadCommand.java
+++ b/src/java/org/apache/cassandra/db/SinglePartitionReadCommand.java
@@ -883,7 +883,6 @@ public class SinglePartitionReadCommand extends ReadCommand
 
         /* add the SSTables on disk */
         Collections.sort(view.sstables, SSTableReader.maxTimestampComparator);
-        boolean onlyUnrepaired = true;
         // read sorted sstables
         SSTableReadMetricsCollector metricsCollector = new SSTableReadMetricsCollector();
         for (SSTableReader sstable : view.sstables)
@@ -952,9 +951,6 @@ public class SinglePartitionReadCommand extends ReadCommand
                 if (iter.isEmpty())
                     continue;
 
-                if (sstable.isRepaired())
-                    onlyUnrepaired = false;
-
                 result = add(
                     RTBoundValidator.validate(isForThrift() ? ThriftResultsMerger.maybeWrap(iter, nowInSec()) : iter, RTBoundValidator.Stage.SSTABLE, false),
                     result,
@@ -972,30 +968,6 @@ public class SinglePartitionReadCommand extends ReadCommand
         DecoratedKey key = result.partitionKey();
         cfs.metric.samplers.get(TableMetrics.Sampler.READS).addSample(key.getKey(), key.hashCode(), 1);
 
-        // "hoist up" the requested data into a more recent sstable
-        if (metricsCollector.getMergedSSTables() > cfs.getMinimumCompactionThreshold()
-            && onlyUnrepaired
-            && !cfs.isAutoCompactionDisabled()
-            && cfs.getCompactionStrategyManager().shouldDefragment())
-        {
-            // !!WARNING!!   if we stop copying our data to a heap-managed object,
-            //               we will need to track the lifetime of this mutation as well
-            Tracing.trace("Defragmenting requested data");
-
-            try (UnfilteredRowIterator iter = result.unfilteredIterator(columnFilter(), Slices.ALL, false))
-            {
-                final Mutation mutation = new Mutation(PartitionUpdate.fromIterator(iter));
-                StageManager.getStage(Stage.MUTATION).execute(new Runnable()
-                {
-                    public void run()
-                    {
-                        // skipping commitlog and index updates is fine since we're just de-fragmenting existing data
-                        Keyspace.open(mutation.getKeyspaceName()).apply(mutation, false, false);
-                    }
-                });
-            }
-        }
-
         return result.unfilteredIterator(columnFilter(), Slices.ALL, clusteringIndexFilter().isReversed());
     }
 
diff --git a/src/java/org/apache/cassandra/db/compaction/AbstractCompactionStrategy.java b/src/java/org/apache/cassandra/db/compaction/AbstractCompactionStrategy.java
index 7219504e9e..3ceda93c15 100644
--- a/src/java/org/apache/cassandra/db/compaction/AbstractCompactionStrategy.java
+++ b/src/java/org/apache/cassandra/db/compaction/AbstractCompactionStrategy.java
@@ -299,11 +299,6 @@ public abstract class AbstractCompactionStrategy
         return new ScannerList(scanners);
     }
 
-    public boolean shouldDefragment()
-    {
-        return false;
-    }
-
     public String getName()
     {
         return getClass().getSimpleName();
diff --git a/src/java/org/apache/cassandra/db/compaction/CompactionStrategyManager.java b/src/java/org/apache/cassandra/db/compaction/CompactionStrategyManager.java
index 1d3d18c312..5d4a254e47 100644
--- a/src/java/org/apache/cassandra/db/compaction/CompactionStrategyManager.java
+++ b/src/java/org/apache/cassandra/db/compaction/CompactionStrategyManager.java
@@ -235,12 +235,6 @@ public class CompactionStrategyManager implements INotificationConsumer
         return res;
     }
 
-    public boolean shouldDefragment()
-    {
-        assert repaired.getClass().equals(unrepaired.getClass());
-        return repaired.shouldDefragment();
-    }
-
     public Directories getDirectories()
     {
         assert repaired.getClass().equals(unrepaired.getClass());
diff --git a/src/java/org/apache/cassandra/db/compaction/SizeTieredCompactionStrategy.java b/src/java/org/apache/cassandra/db/compaction/SizeTieredCompactionStrategy.java
index 80f5e8cba5..dae3a7867d 100644
--- a/src/java/org/apache/cassandra/db/compaction/SizeTieredCompactionStrategy.java
+++ b/src/java/org/apache/cassandra/db/compaction/SizeTieredCompactionStrategy.java
@@ -309,12 +309,6 @@ public class SizeTieredCompactionStrategy extends AbstractCompactionStrategy
         return uncheckedOptions;
     }
 
-    @Override
-    public boolean shouldDefragment()
-    {
-        return true;
-    }
-
     @Override
     public synchronized void addSSTable(SSTableReader added)
     {