diff --git a/packages/mermaid/src/diagrams/class/classRenderer-v2.ts b/packages/mermaid/src/diagrams/class/classRenderer-v2.ts
index 00688d366..97106a169 100644
--- a/packages/mermaid/src/diagrams/class/classRenderer-v2.ts
+++ b/packages/mermaid/src/diagrams/class/classRenderer-v2.ts
@@ -231,7 +231,7 @@ export const addRelations = function (relations: ClassRelation[], g: graphlib.Gr
       //Set relationship style and line type
       classes: 'relation',
       pattern: edge.relation.lineType == 1 ? 'dashed' : 'solid',
-      id: 'id_' + edge.id1 + '_' + edge.id2 + '_' + cnt,
+      id: `id_${edge.id1}_${edge.id2}_${cnt}`,
       // Set link type for rendering
       arrowhead: edge.type === 'arrow_open' ? 'none' : 'normal',
       //Set edge extra labels