diff --git a/packages/mindplot/src/components/export/FreemindExporter.ts b/packages/mindplot/src/components/export/FreemindExporter.ts
index 4c71b55f..cddfe5e6 100644
--- a/packages/mindplot/src/components/export/FreemindExporter.ts
+++ b/packages/mindplot/src/components/export/FreemindExporter.ts
@@ -254,11 +254,11 @@ class FreemindExporter extends Exporter {
   }
 
   private addFontNode(freemindNode: FreeminNode, mindmapTopic: INodeModel): void {
-    const fontFamily: string = mindmapTopic.getFontFamily();
-    const fontSize: number = mindmapTopic.getFontSize();
-    const fontColor: string = mindmapTopic.getFontColor();
+    const fontFamily: string | undefined = mindmapTopic.getFontFamily();
+    const fontSize: number | undefined = mindmapTopic.getFontSize();
+    const fontColor: string | undefined = mindmapTopic.getFontColor();
     const fontWeigth: string | number | boolean | undefined = mindmapTopic.getFontWeight();
-    const fontStyle: string = mindmapTopic.getFontStyle();
+    const fontStyle: string | undefined = mindmapTopic.getFontStyle();
 
     if (fontFamily || fontSize || fontColor || fontWeigth || fontStyle) {
       const font: Font = this.objectFactory.createFont();
diff --git a/packages/mindplot/src/components/model/INodeModel.ts b/packages/mindplot/src/components/model/INodeModel.ts
index 8fcca1c8..04e5c2c7 100644
--- a/packages/mindplot/src/components/model/INodeModel.ts
+++ b/packages/mindplot/src/components/model/INodeModel.ts
@@ -159,7 +159,7 @@ abstract class INodeModel {
     this.putProperty('fontFamily', fontFamily);
   }
 
-  getFontFamily(): string {
+  getFontFamily(): string | undefined {
     return this.getProperty('fontFamily') as string;
   }
 
@@ -167,11 +167,11 @@ abstract class INodeModel {
     this.putProperty('fontStyle', fontStyle);
   }
 
-  getFontStyle(): FontStyleType {
+  getFontStyle(): FontStyleType | undefined {
     return this.getProperty('fontStyle') as FontStyleType;
   }
 
-  setFontWeight(weight: FontWeightType) {
+  setFontWeight(weight: FontWeightType): void {
     this.putProperty('fontWeight', weight);
   }