diff --git a/packages/react-diagrams-core/src/entities/link/LinkWidget.tsx b/packages/react-diagrams-core/src/entities/link/LinkWidget.tsx
index a64c081..5f64cb2 100644
--- a/packages/react-diagrams-core/src/entities/link/LinkWidget.tsx
+++ b/packages/react-diagrams-core/src/entities/link/LinkWidget.tsx
@@ -47,6 +47,8 @@ export class LinkWidget extends React.Component<LinkProps, LinkState> {
 
 	installTarget() {
 		this.targetListener && this.targetListener.deregister();
+
+		if (!this.props.link.getTargetPort()) return;
 		this.targetListener = this.props.link.getTargetPort().registerListener({
 			reportInitialPosition: (event: BaseEntityEvent<BasePositionModel>) => {
 				this.forceUpdate();
@@ -56,6 +58,8 @@ export class LinkWidget extends React.Component<LinkProps, LinkState> {
 
 	installSource() {
 		this.sourceListener && this.sourceListener.deregister();
+
+		if (!this.props.link.getSourcePort()) return;
 		this.sourceListener = this.props.link.getSourcePort().registerListener({
 			reportInitialPosition: (event: BaseEntityEvent<BasePositionModel>) => {
 				this.forceUpdate();
diff --git a/packages/react-diagrams-core/src/entities/node/NodeWidget.tsx b/packages/react-diagrams-core/src/entities/node/NodeWidget.tsx
index 271b268..1070151 100644
--- a/packages/react-diagrams-core/src/entities/node/NodeWidget.tsx
+++ b/packages/react-diagrams-core/src/entities/node/NodeWidget.tsx
@@ -36,6 +36,9 @@ export class NodeWidget extends React.Component<NodeProps> {
 	componentWillUnmount(): void {
 		this.ob.disconnect();
 		this.ob = null;
+
+		this.listener.deregister();
+		this.listener = null;
 	}
 
 	componentDidUpdate(prevProps: Readonly<NodeProps>, prevState: Readonly<any>, snapshot?: any): void {