diff --git a/core/block_svg.ts b/core/block_svg.ts
index bc02ef63810..ac6970dced8 100644
--- a/core/block_svg.ts
+++ b/core/block_svg.ts
@@ -849,7 +849,7 @@ export class BlockSvg
    * @internal
    */
   applyColour() {
-    this.pathObject.applyColour(this);
+    this.pathObject.applyColour?.(this);
 
     const icons = this.getIcons();
     for (let i = 0; i < icons.length; i++) {
@@ -1115,7 +1115,7 @@ export class BlockSvg
       .getConstants()
       .getBlockStyleForColour(this.colour_);
 
-    this.pathObject.setStyle(styleObj.style);
+    this.pathObject.setStyle?.(styleObj.style);
     this.style = styleObj.style;
     this.styleName_ = styleObj.name;
 
@@ -1137,7 +1137,7 @@ export class BlockSvg
 
     if (blockStyle) {
       this.hat = blockStyle.hat;
-      this.pathObject.setStyle(blockStyle);
+      this.pathObject.setStyle?.(blockStyle);
       // Set colour to match Block.
       this.colour_ = blockStyle.colourPrimary;
       this.style = blockStyle;
diff --git a/core/renderers/common/i_path_object.ts b/core/renderers/common/i_path_object.ts
index 30033f18e81..cb647520257 100644
--- a/core/renderers/common/i_path_object.ts
+++ b/core/renderers/common/i_path_object.ts
@@ -49,21 +49,6 @@ export interface IPathObject {
    */
   setPath(pathString: string): void;
 
-  /**
-   * Apply the stored colours to the block's path, taking into account whether
-   * the paths belong to a shadow block.
-   *
-   * @param block The source block.
-   */
-  applyColour(block: BlockSvg): void;
-
-  /**
-   * Update the style.
-   *
-   * @param blockStyle The block style to use.
-   */
-  setStyle(blockStyle: BlockStyle): void;
-
   /**
    * Flip the SVG paths in RTL.
    */
@@ -130,8 +115,23 @@ export interface IPathObject {
     rtl: boolean,
   ): void;
 
+  /**
+   * Apply the stored colours to the block's path, taking into account whether
+   * the paths belong to a shadow block.
+   *
+   * @param block The source block.
+   */
+  applyColour?(block: BlockSvg): void;
+
   /**
    * Removes any highlight associated with the given connection, if it exists.
    */
   removeConnectionHighlight?(connection: RenderedConnection): void;
+
+  /**
+   * Update the style.
+   *
+   * @param blockStyle The block style to use.
+   */
+  setStyle?(blockStyle: BlockStyle): void;
 }