diff --git a/spec/gridstack-spec.ts b/spec/gridstack-spec.ts
index ebcb35bc..faf3e4bc 100644
--- a/spec/gridstack-spec.ts
+++ b/spec/gridstack-spec.ts
@@ -1435,7 +1435,7 @@ describe('gridstack >', function() {
         float: false,
       };
       var grid = GridStack.init(options);
-      expect((grid as any)._styles.ownerNode.parentNode.tagName).toBe('DIV'); // any to access private _styles
+      expect((grid as any)._styles.parentElement.tagName).toBe('DIV'); // any to access private _styles
     });
     it('should add STYLE to HEAD if styleInHead === true >', function() {
       var options = {
@@ -1445,7 +1445,7 @@ describe('gridstack >', function() {
         styleInHead: true
       };
       var grid = GridStack.init(options);
-      expect((grid as any)._styles.ownerNode.parentNode.tagName).toBe('HEAD'); // any to access private _styles
+      expect((grid as any)._styles.parentElement.tagName).toBe('HEAD'); // any to access private _styles
     });
   });
 
@@ -1458,11 +1458,11 @@ describe('gridstack >', function() {
     });
     it('should add STYLE to parent node as a default >', function() {
       var grid = GridStack.init();
-      expect((grid as any)._styles.ownerNode.parentNode.tagName).toBe('DIV');
+      expect((grid as any)._styles.parentElement.tagName).toBe('DIV');
     });
     it('should add STYLE to HEAD if styleInHead === true >', function() {
       var grid = GridStack.init({styleInHead: true});
-      expect((grid as any)._styles.ownerNode.parentNode.tagName).toBe('HEAD');
+      expect((grid as any)._styles.parentElement.tagName).toBe('HEAD');
     });
   });
 
diff --git a/src/gridstack.ts b/src/gridstack.ts
index a47fb417..c6391469 100644
--- a/src/gridstack.ts
+++ b/src/gridstack.ts
@@ -992,10 +992,10 @@ export class GridStack {
       this.el.parentNode.removeChild(this.el);
     }
     this._removeStylesheet();
-    if (this.parentGridNode) delete this.parentGridNode.subGrid;
+    delete this.parentGridNode?.subGrid;
     delete this.parentGridNode;
     delete this.opts;
-    delete this._placeholder.gridstackNode;
+    delete this._placeholder?.gridstackNode;
     delete this._placeholder;
     delete this.engine;
     delete this.el.gridstack; // remove circular dependency that would prevent a freeing