diff --git a/core/renderers/block_rendering_rewrite/block_render_draw_debug.js b/core/renderers/block_rendering_rewrite/block_render_draw_debug.js
index 33869480e..91456bc64 100644
--- a/core/renderers/block_rendering_rewrite/block_render_draw_debug.js
+++ b/core/renderers/block_rendering_rewrite/block_render_draw_debug.js
@@ -84,20 +84,23 @@ Blockly.blockRendering.Debug.prototype.drawSpacerRow = function(row, cursorY) {
  * @param {!Blockly.BlockSvg.InRowSpacer} elem The spacer to render
  * @param {number} cursorX The x position of the left of the row.
  * @param {number} centerY The y position of the center of the row, vertically.
+ * @param {number} rowHeight The height of the container row.
  * @package
  */
-Blockly.blockRendering.Debug.prototype.drawSpacerElem = function(elem, cursorX, centerY) {
-  var yPos = centerY - elem.height / 2;
-  this.debugElements_.push(Blockly.utils.dom.createSvgElement('rect',
-      {
-        'class': 'elemSpacerRect blockRenderDebug',
-        'x': cursorX,
-        'y': yPos,
-        'width': elem.width,
-        'height': 15,
-      },
-      this.svgRoot_));
-};
+Blockly.blockRendering.Debug.prototype.drawSpacerElem =
+    function(elem, cursorX,  centerY, rowHeight) {
+      var debugRenderedHeight = Math.min(15, rowHeight);
+      var yPos = centerY - debugRenderedHeight / 2;
+      this.debugElements_.push(Blockly.utils.dom.createSvgElement('rect',
+          {
+            'class': 'elemSpacerRect blockRenderDebug',
+            'x': cursorX,
+            'y': yPos,
+            'width': elem.width,
+            'height': debugRenderedHeight,
+          },
+          this.svgRoot_));
+    };
 
 /**
  * Draw a debug rectangle for an in-row element.
@@ -193,7 +196,7 @@ Blockly.blockRendering.Debug.prototype.drawRowWithElements = function(row, curso
   for (var e = 0; e < row.elements.length; e++) {
     var elem = row.elements[e];
     if (elem.isSpacer()) {
-      this.drawSpacerElem(elem, cursorX, centerY);
+      this.drawSpacerElem(elem, cursorX, centerY, row.height);
     } else {
       this.drawRenderedElem(elem, cursorX, centerY);
     }
diff --git a/core/renderers/block_rendering_rewrite/measurables.js b/core/renderers/block_rendering_rewrite/measurables.js
index 514f087ab..2ae3c3a02 100644
--- a/core/renderers/block_rendering_rewrite/measurables.js
+++ b/core/renderers/block_rendering_rewrite/measurables.js
@@ -453,11 +453,6 @@ Blockly.blockRendering.TopRow = function(block) {
 };
 goog.inherits(Blockly.blockRendering.TopRow, Blockly.blockRendering.Row);
 
-
-Blockly.blockRendering.TopRow.prototype.isSpacer = function() {
-  return true;
-};
-
 Blockly.blockRendering.BottomRow = function(block) {
   Blockly.blockRendering.BottomRow.superClass_.constructor.call(this);
   this.type = 'bottom row';
@@ -480,8 +475,3 @@ Blockly.blockRendering.BottomRow = function(block) {
 };
 goog.inherits(Blockly.blockRendering.BottomRow,
     Blockly.blockRendering.Row);
-
-Blockly.blockRendering.BottomRow.prototype.isSpacer = function() {
-  return true;
-};
-