diff --git a/history.txt b/history.txt
index e9c588461b..20ba7b1649 100644
--- a/history.txt
+++ b/history.txt
@@ -1,3 +1,8 @@
+2018-09-22 zzz
+ * NTCP:
+   - Fix handling of multiple connections
+   - Change termination code for expired RI
+
 2018-09-16 zzz
  * Build: Fix hang with Tomcat 8.5.33+ (ticket #2307)
  * Tomcat 8.5.34
diff --git a/router/java/src/net/i2p/router/RouterVersion.java b/router/java/src/net/i2p/router/RouterVersion.java
index f6e6df3a5c..ba403a9f3e 100644
--- a/router/java/src/net/i2p/router/RouterVersion.java
+++ b/router/java/src/net/i2p/router/RouterVersion.java
@@ -18,10 +18,10 @@ public class RouterVersion {
     /** deprecated */
     public final static String ID = "Monotone";
     public final static String VERSION = CoreVersion.VERSION;
-    public final static long BUILD = 4;
+    public final static long BUILD = 5;
 
     /** for example "-test" */
-    public final static String EXTRA = "";
+    public final static String EXTRA = "-rc";
     public final static String FULL_VERSION = VERSION + "-" + BUILD + EXTRA;
     public static void main(String args[]) {
         System.out.println("I2P Router version: " + FULL_VERSION);
diff --git a/router/java/src/net/i2p/router/transport/ntcp/InboundEstablishState.java b/router/java/src/net/i2p/router/transport/ntcp/InboundEstablishState.java
index eea0071968..38066761e0 100644
--- a/router/java/src/net/i2p/router/transport/ntcp/InboundEstablishState.java
+++ b/router/java/src/net/i2p/router/transport/ntcp/InboundEstablishState.java
@@ -1002,8 +1002,9 @@ class InboundEstablishState extends EstablishBase implements NTCP2Payload.Payloa
             }
         } catch (IllegalArgumentException iae) {
             // hash collision?
-            _msg3p2FailReason = NTCPConnection.REASON_UNSPEC;
-            throw new DataFormatException("RI store fail", iae);
+            // expired RI?
+            _msg3p2FailReason = NTCPConnection.REASON_MSG3;
+            throw new DataFormatException("RI store fail: " + ri, iae);
         }
         _con.setRemotePeer(_aliceIdent);
     }
diff --git a/router/java/src/net/i2p/router/transport/ntcp/NTCPConnection.java b/router/java/src/net/i2p/router/transport/ntcp/NTCPConnection.java
index aa66d552d5..de32aace41 100644
--- a/router/java/src/net/i2p/router/transport/ntcp/NTCPConnection.java
+++ b/router/java/src/net/i2p/router/transport/ntcp/NTCPConnection.java
@@ -488,6 +488,7 @@ public class NTCPConnection implements Closeable {
         }
         NTCPConnection toClose = locked_close(allowRequeue);
         if (toClose != null && toClose != this) {
+            // won't happen as of 0.9.37
             if (_log.shouldLog(Log.WARN))
                 _log.warn("Multiple connections on remove, closing " + toClose + " (already closed " + this + ")");
             _context.statManager().addRateData("ntcp.multipleCloseOnRemove", toClose.getUptime());
@@ -507,7 +508,8 @@ public class NTCPConnection implements Closeable {
     }
 
     /**
-     * @return a second connection with the same peer...
+     * @return usually this, but could be a second connection with the same peer...
+     *         only this or null as of 0.9.37
      */
     private synchronized NTCPConnection locked_close(boolean allowRequeue) {
         if (_chan != null) try { _chan.close(); } catch (IOException ioe) { }
@@ -1834,9 +1836,9 @@ public class NTCPConnection implements Closeable {
             _paddingConfig = OUR_PADDING;
         }
         NTCPConnection toClose = _transport.inboundEstablished(this);
-        if (toClose != null) {
-            if (_log.shouldLog(Log.DEBUG))
-                _log.debug("Old connection closed: " + toClose + " replaced by " + this);
+        if (toClose != null && toClose != this) {
+            if (_log.shouldWarn())
+                _log.warn("Old connection closed: " + toClose + " replaced by " + this);
             _context.statManager().addRateData("ntcp.inboundEstablishedDuplicate", toClose.getUptime());
             toClose.close();
         }
@@ -2107,7 +2109,7 @@ public class NTCPConnection implements Closeable {
                     }
                 }
             } catch (IllegalArgumentException iae) {
-                throw new DataFormatException("RI store fail", iae);
+                throw new DataFormatException("RI store fail: " + ri, iae);
             }
         }
 
diff --git a/router/java/src/net/i2p/router/transport/ntcp/NTCPTransport.java b/router/java/src/net/i2p/router/transport/ntcp/NTCPTransport.java
index 29523181dd..e19d89645e 100644
--- a/router/java/src/net/i2p/router/transport/ntcp/NTCPTransport.java
+++ b/router/java/src/net/i2p/router/transport/ntcp/NTCPTransport.java
@@ -73,7 +73,7 @@ public class NTCPTransport extends TransportImpl {
     private final SharedBid _nearCapacityCostBid;
     private final SharedBid _transientFail;
     private final Object _conLock;
-    private final Map<Hash, NTCPConnection> _conByIdent;
+    private final ConcurrentHashMap<Hash, NTCPConnection> _conByIdent;
     private final EventPumper _pumper;
     private final Reader _reader;
     private net.i2p.router.transport.ntcp.Writer _writer;
@@ -641,13 +641,17 @@ public class NTCPTransport extends TransportImpl {
 
     /**
      * @return usually the con passed in, but possibly a second connection with the same peer...
+     *         only con or null as of 0.9.37
      */
     NTCPConnection removeCon(NTCPConnection con) {
         NTCPConnection removed = null;
         RouterIdentity ident = con.getRemotePeer();
         if (ident != null) {
             synchronized (_conLock) {
-                removed = _conByIdent.remove(ident.calculateHash());
+                // only remove the con passed in
+                //removed = _conByIdent.remove(ident.calculateHash());
+                if (_conByIdent.remove(ident.calculateHash(), con))
+                    removed = con;
             }
         }
         return removed;