diff --git a/CHANGES.txt b/CHANGES.txt
index 7863d56e3f..ac3a1574d6 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,4 +1,5 @@
 1.1.6
+ * fix commitlog replay for nanotime-infected sstables (CASSANDRA-4782)
  * preflight check ttl for maximum of 20 years (CASSANDRA-4771)
  * Fix HH to compact with correct gcBefore, which avoids wiping out
    undelivered hints (CASSANDRA-4772)
diff --git a/NEWS.txt b/NEWS.txt
index a2d0ce1952..667a055dbd 100644
--- a/NEWS.txt
+++ b/NEWS.txt
@@ -14,8 +14,10 @@ by version X, but the inverse is not necessarily the case.)
 
 Upgrading
 ---------
-    - Nothing specific to this release, but please see 1.1 if you are upgrading
-      from a previous version.
+    - If you are using counters, you should drain existing Cassandra nodes
+      prior to the upgrade to prevent overcount during commitlog replay
+      (see CASSANDRA-4782).  For non-counter uses, drain is not required
+      but is a good practice to minimize restart time.
 
 
 1.1.5
diff --git a/src/java/org/apache/cassandra/io/sstable/Descriptor.java b/src/java/org/apache/cassandra/io/sstable/Descriptor.java
index d35865c692..f4663b735c 100644
--- a/src/java/org/apache/cassandra/io/sstable/Descriptor.java
+++ b/src/java/org/apache/cassandra/io/sstable/Descriptor.java
@@ -59,7 +59,8 @@ public class Descriptor
     // hc (1.0.4): records partitioner in metadata component
     // hd (1.0.10): includes row tombstones in maxtimestamp
     // he (1.1.3): includes ancestors generation in metadata component
-    public static final String CURRENT_VERSION = "he";
+    // hf (1.1.6): marker that replay position corresponds to 1.1.5+ millis-based id (see CASSANDRA-4782)
+    public static final String CURRENT_VERSION = "hf";
 
     public final File directory;
     /** version has the following format: <code>[a-z]+</code> */
@@ -76,6 +77,7 @@ public class Descriptor
     public final boolean isLatestVersion;
     public final boolean usesOldBloomFilter;
     public final boolean metadataIncludesReplayPosition;
+    public final boolean metadataIncludesModernReplayPosition;
     public final boolean tracksMaxTimestamp;
     public final boolean hasCompressionRatio;
     public final boolean hasPartitioner;
@@ -109,6 +111,7 @@ public class Descriptor
         hasCompressionRatio = version.compareTo("hb") >= 0;
         hasPartitioner = version.compareTo("hc") >= 0;
         hasAncestors = version.compareTo("he") >= 0;
+        metadataIncludesModernReplayPosition = version.compareTo("hf") >= 0;
         isLatestVersion = version.compareTo(CURRENT_VERSION) == 0;
     }
 
diff --git a/src/java/org/apache/cassandra/io/sstable/SSTableMetadata.java b/src/java/org/apache/cassandra/io/sstable/SSTableMetadata.java
index 147f2b2376..302fb50cba 100644
--- a/src/java/org/apache/cassandra/io/sstable/SSTableMetadata.java
+++ b/src/java/org/apache/cassandra/io/sstable/SSTableMetadata.java
@@ -217,6 +217,12 @@ public class SSTableMetadata
             ReplayPosition replayPosition = desc.metadataIncludesReplayPosition
                                           ? ReplayPosition.serializer.deserialize(dis)
                                           : ReplayPosition.NONE;
+            if (!desc.metadataIncludesModernReplayPosition)
+            {
+                // replay position may be "from the future" thanks to older versions generating them with nanotime.
+                // make sure we don't omit replaying something that we should.  see CASSANDRA-4782
+                replayPosition = ReplayPosition.NONE;
+            }
             long maxTimestamp = desc.containsTimestamp() ? dis.readLong() : Long.MIN_VALUE;
             if (!desc.tracksMaxTimestamp) // see javadoc to Descriptor.containsTimestamp
                 maxTimestamp = Long.MIN_VALUE;