diff --git a/packages/mermaid/src/diagrams/sankey/sankeyDiagram.ts b/packages/mermaid/src/diagrams/sankey/sankeyDiagram.ts
index df32523e8..4fce38f97 100644
--- a/packages/mermaid/src/diagrams/sankey/sankeyDiagram.ts
+++ b/packages/mermaid/src/diagrams/sankey/sankeyDiagram.ts
@@ -2,6 +2,7 @@ import { DiagramDefinition } from '../../diagram-api/types.js';
 // @ts-ignore: jison doesn't export types
 import parser from './parser/sankey.jison';
 import db from './sankeyDB.js';
+import styles from './styles.js';
 import renderer from './sankeyRenderer.js';
 import { prepareTextForParsing } from './sankeyUtils.js';
 
@@ -12,5 +13,5 @@ export const diagram: DiagramDefinition = {
   parser,
   db,
   renderer,
-  styles: () => {},
+  styles,
 };
diff --git a/packages/mermaid/src/diagrams/sankey/styles.js b/packages/mermaid/src/diagrams/sankey/styles.js
new file mode 100644
index 000000000..54881fe6f
--- /dev/null
+++ b/packages/mermaid/src/diagrams/sankey/styles.js
@@ -0,0 +1,5 @@
+const getStyles = (options) =>
+  `
+`;
+
+export default getStyles;
diff --git a/packages/mermaid/src/styles.spec.ts b/packages/mermaid/src/styles.spec.ts
index af076b6f9..d1edf4111 100644
--- a/packages/mermaid/src/styles.spec.ts
+++ b/packages/mermaid/src/styles.spec.ts
@@ -29,6 +29,7 @@ import state from './diagrams/state/styles.js';
 import journey from './diagrams/user-journey/styles.js';
 import timeline from './diagrams/timeline/styles.js';
 import mindmap from './diagrams/mindmap/styles.js';
+import sankey from './diagrams/sankey/styles.js';
 import themes from './themes/index.js';
 
 async function checkValidStylisCSSStyleSheet(stylisString: string) {
@@ -98,7 +99,7 @@ describe('styles', () => {
         sequence,
         state,
         timeline,
-        sankey: () => {},
+        sankey,
       })) {
         test(`should return a valid style for diagram ${diagramId} and theme ${themeId}`, async () => {
           const { default: getStyles, addStylesForDiagram } = await import('./styles.js');