diff --git a/packages/mermaid/src/diagrams/pie/pieRenderer.js b/packages/mermaid/src/diagrams/pie/pieRenderer.js
index ca88d58a6ed..67db0ed02e0 100644
--- a/packages/mermaid/src/diagrams/pie/pieRenderer.js
+++ b/packages/mermaid/src/diagrams/pie/pieRenderer.js
@@ -4,7 +4,7 @@ import { log } from '../../logger.js';
 import { configureSvgSize } from '../../setupGraphViewbox.js';
 import * as configApi from '../../config.js';
 import { parseFontSize } from '../../utils.js';
-import { getTextWidth } from '../../rendering-util/getTextWidth.ts';
+import { getTextWidth } from '../../rendering-util/getTextWidth.js';
 
 let conf = configApi.getConfig();
 
diff --git a/packages/mermaid/src/rendering-util/getTextWidth.js b/packages/mermaid/src/rendering-util/getTextWidth.js
new file mode 100644
index 00000000000..f2976a852a4
--- /dev/null
+++ b/packages/mermaid/src/rendering-util/getTextWidth.js
@@ -0,0 +1,7 @@
+// https://stackoverflow.com/a/35373030/3469145
+const canvas = document.createElement('canvas');
+const context = canvas.getContext('2d');
+
+const getTextWidth = (text) => context.measureText(text).width * window.devicePixelRatio;
+
+export { getTextWidth };
diff --git a/packages/mermaid/src/rendering-util/getTextWidth.ts b/packages/mermaid/src/rendering-util/getTextWidth.ts
deleted file mode 100644
index da44f2a3fb3..00000000000
--- a/packages/mermaid/src/rendering-util/getTextWidth.ts
+++ /dev/null
@@ -1,7 +0,0 @@
-// https://stackoverflow.com/a/35373030/3469145
-const canvas = document.createElement('canvas');
-const context = canvas.getContext('2d') as CanvasRenderingContext2D;
-
-const getTextWidth = (text: string) => context.measureText(text).width * window.devicePixelRatio;
-
-export { getTextWidth };