diff --git a/ChangeLog b/ChangeLog
index 9386e5ab6..8c62c2a1e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -17,6 +17,7 @@ Features
  + #1297 The task₋sync(5) man pages is rewritten with examples.
  + #1339 The configuration file now supports JSON encoding of Unicode
    characters, by specifying \uNNNN.
+ + #1423 sync vs. push, pull, merge collision avoidance.
  + #1385 Need a way to configure the trust of self-signed certificates.
  + Stores un-synched transactions in <data.location>/backlog.data.
  + Adds a new 'synchronize' command to sync data with a task server.
diff --git a/src/commands/CmdShow.cpp b/src/commands/CmdShow.cpp
index 5b13bbf41..b2fa840ac 100644
--- a/src/commands/CmdShow.cpp
+++ b/src/commands/CmdShow.cpp
@@ -168,7 +168,7 @@ int CmdShow::execute (std::string& output)
     " list.all.tags"
     " locale"
     " locking"
-    " merge.autopush"
+    " merge.autopush"                    // Deprecated 2.3.0
     " merge.default.uri"                 // Deprecated 2.3.0
     " monthsperline"
     " nag"
@@ -300,19 +300,7 @@ int CmdShow::execute (std::string& output)
         color = warning;
       }
 
-      // TODO Deprecated.
       std::string value = i->second;
-      // hide sensible information
-      if ((i->first.substr (0, 5) == "push."   ||
-            i->first.substr (0, 5) == "pull."   ||
-            i->first.substr (0, 6) == "merge.") &&
-          (i->first.find (".uri") != std::string::npos))
-      {
-        Uri uri (value);
-        uri.parse ();
-        value = uri.ToString ();
-      }
-
       int row = view.addRow ();
       view.set (row, 0, i->first, color);
       view.set (row, 1, value, color);
diff --git a/src/commands/CmdSync.cpp b/src/commands/CmdSync.cpp
index 153f7d9a8..715abf645 100644
--- a/src/commands/CmdSync.cpp
+++ b/src/commands/CmdSync.cpp
@@ -78,6 +78,13 @@ int CmdSync::execute (std::string& output)
       connection.rfind (':') == std::string::npos)
     throw std::string (STRING_CMD_SYNC_NO_SERVER);
 
+  // If push/pull/merge is configured, quit.
+  if (context.config.get ("merge.autopush")    != "" ||
+      context.config.get ("merge.default.uri") != "" ||
+      context.config.get ("push.default.uri")  != "" ||
+      context.config.get ("pull.default.uri")  != "")
+    throw std::string (STRING_CMD_SYNC_NOMERGE);
+
   // Obtain credentials.
   std::string credentials_string = context.config.get ("taskd.credentials");
   if (credentials_string == "")
diff --git a/src/en-US.h b/src/en-US.h
index 4ae879cfd..ab8e7acb8 100644
--- a/src/en-US.h
+++ b/src/en-US.h
@@ -428,6 +428,7 @@
 #define STRING_CMD_SYNC_NO_CA        "CA certificate not found."
 #define STRING_CMD_SYNC_CONNECT      "Could not connect to {1} {2}"
 #define STRING_CMD_SYNC_HANDSHAKE    "Handshake failed.  {1}"
+#define STRING_CMD_SYNC_NOMERGE      "Task push/pull/merge is configured, deprecated, and does not work with 'sync'."
 #define STRING_CMD_DIAG_USAGE        "Platform, build and environment details"
 #define STRING_CMD_DIAG_PLATFORM     "Platform"
 #define STRING_CMD_DIAG_UNKNOWN      "<unknown>"
diff --git a/src/es-ES.h b/src/es-ES.h
index b0478dcc3..7c2e4ff59 100644
--- a/src/es-ES.h
+++ b/src/es-ES.h
@@ -439,6 +439,7 @@
 #define STRING_CMD_SYNC_NO_CA        "Certificado CA no encontrado."
 #define STRING_CMD_SYNC_CONNECT      "No se pudo conectar a {1} {2}"
 #define STRING_CMD_SYNC_HANDSHAKE    "Handshake fallido.  {1}"
+#define STRING_CMD_SYNC_NOMERGE      "Task push/pull/merge is configured, deprecated, and does not work with 'sync'."
 #define STRING_CMD_DIAG_USAGE        "Detalles de plataforma, construcción y entorno"
 #define STRING_CMD_DIAG_PLATFORM     "Plataforma"
 #define STRING_CMD_DIAG_UNKNOWN      "<desconocido>"
diff --git a/src/fr-FR.h b/src/fr-FR.h
index 366e224fc..0be2a7960 100644
--- a/src/fr-FR.h
+++ b/src/fr-FR.h
@@ -428,6 +428,7 @@
 #define STRING_CMD_SYNC_NO_CA        "CA certificate not found."
 #define STRING_CMD_SYNC_CONNECT      "Could not connect to {1} {2}"
 #define STRING_CMD_SYNC_HANDSHAKE    "Handshake failed.  {1}"
+#define STRING_CMD_SYNC_NOMERGE      "Task push/pull/merge is configured, deprecated, and does not work with 'sync'."
 #define STRING_CMD_DIAG_USAGE        "Platform, build and environment details"
 #define STRING_CMD_DIAG_PLATFORM     "Platform"
 #define STRING_CMD_DIAG_UNKNOWN      "<unknown>"
diff --git a/src/it-IT.h b/src/it-IT.h
index 3c0274c3d..0653e1dcf 100644
--- a/src/it-IT.h
+++ b/src/it-IT.h
@@ -429,6 +429,7 @@
 #define STRING_CMD_SYNC_NO_CA        "CA certificate not found."
 #define STRING_CMD_SYNC_CONNECT      "Could not connect to {1} {2}"
 #define STRING_CMD_SYNC_HANDSHAKE    "Handshake failed.  {1}"
+#define STRING_CMD_SYNC_NOMERGE      "Task push/pull/merge is configured, deprecated, and does not work with 'sync'."
 #define STRING_CMD_DIAG_USAGE        "Dettagli su piattaforma, build e ambiente"
 #define STRING_CMD_DIAG_PLATFORM     "Piattaforma"
 #define STRING_CMD_DIAG_UNKNOWN      "<sconoscito>"