diff --git a/core/connection_db.js b/core/connection_db.js
index ce7e9487b..a09a33945 100644
--- a/core/connection_db.js
+++ b/core/connection_db.js
@@ -49,16 +49,12 @@ Blockly.ConnectionDB = function() {
  * @param {!Blockly.Connection} connection The connection to be added.
  */
 Blockly.ConnectionDB.prototype.addConnection = function(connection) {
-  if (connection.inDB_) {
-    throw Error('Connection already in database.');
-  }
   if (connection.getSourceBlock().isInFlyout) {
     // Don't bother maintaining a database of connections in a flyout.
     return;
   }
   var position = this.findPositionForConnection_(connection);
   this.connections_.splice(position, 0, connection);
-  connection.inDB_ = true;
 };
 
 /**
@@ -136,14 +132,10 @@ Blockly.ConnectionDB.prototype.findPositionForConnection_ = function(
  * @private
  */
 Blockly.ConnectionDB.prototype.removeConnection_ = function(connection) {
-  if (!connection.inDB_) {
-    throw Error('Connection not in database.');
-  }
   var removalIndex = this.findConnection(connection);
   if (removalIndex == -1) {
     throw Error('Unable to find connection in connectionDB.');
   }
-  connection.inDB_ = false;
   this.connections_.splice(removalIndex, 1);
 };
 
@@ -207,7 +199,6 @@ Blockly.ConnectionDB.prototype.getNeighbours = function(connection, maxRadius) {
   return neighbours;
 };
 
-
 /**
  * Is the candidate connection close to the reference connection.
  * Extremely fast; only looks at Y distance.
diff --git a/core/rendered_connection.js b/core/rendered_connection.js
index 5320f819d..79d49af69 100644
--- a/core/rendered_connection.js
+++ b/core/rendered_connection.js
@@ -68,18 +68,11 @@ Blockly.RenderedConnection = function(source, type) {
   this.offsetInBlock_ = new Blockly.utils.Coordinate(0, 0);
 
   /**
-   * Has this connection been added to the connection database?
+   * Whether this connections is tracked in the database or not.
    * @type {boolean}
    * @private
    */
-  this.inDB_ = false;
-
-  /**
-   * Whether this connections is hidden (not tracked in a database) or not.
-   * @type {boolean}
-   * @private
-   */
-  this.hidden_ = !this.db_;
+  this.tracked_ = false;
 };
 Blockly.utils.object.inherits(Blockly.RenderedConnection, Blockly.Connection);
 
@@ -87,7 +80,7 @@ Blockly.utils.object.inherits(Blockly.RenderedConnection, Blockly.Connection);
  * @override
  */
 Blockly.RenderedConnection.prototype.dispose = function() {
-  if (this.inDB_) {
+  if (this.tracked_) {
     this.db_.removeConnection_(this);
   }
   Blockly.RenderedConnection.superClass_.dispose.call(this);
@@ -161,16 +154,12 @@ Blockly.RenderedConnection.prototype.bumpAwayFrom_ = function(staticConnection)
  * @param {number} y New absolute y coordinate, in workspace coordinates.
  */
 Blockly.RenderedConnection.prototype.moveTo = function(x, y) {
-  // Remove it from its old location in the database (if already present)
-  if (this.inDB_) {
+  if (this.tracked_) {
     this.db_.removeConnection_(this);
+    this.db_.addConnection(this);
   }
   this.x_ = x;
   this.y_ = y;
-  // Insert it into its new location in the database.
-  if (!this.hidden_) {
-    this.db_.addConnection(this);
-  }
 };
 
 /**
@@ -338,12 +327,17 @@ Blockly.RenderedConnection.prototype.unhighlight = function() {
  * @param {boolean} hidden True if connection is hidden.
  */
 Blockly.RenderedConnection.prototype.setHidden = function(hidden) {
-  this.hidden_ = hidden;
-  if (hidden && this.inDB_) {
-    this.db_.removeConnection_(this);
-  } else if (!hidden && !this.inDB_) {
-    this.db_.addConnection(this);
+  // Temporary: if we're setting hidden to true we want to set tracked to false.
+  var track = !hidden;
+  if (track == this.tracked_) {
+    return;
   }
+  if (track) {
+    this.db_.addConnection(this);
+  } else {
+    this.db_.removeConnection_(this);
+  }
+  this.tracked_ = track;
 };
 
 /**