diff --git a/packages/mermaid/src/dagre-wrapper/shapes/util.js b/packages/mermaid/src/dagre-wrapper/shapes/util.js
index 1d0d2d77e6..7d1896c9a6 100644
--- a/packages/mermaid/src/dagre-wrapper/shapes/util.js
+++ b/packages/mermaid/src/dagre-wrapper/shapes/util.js
@@ -104,6 +104,7 @@ export const labelHelper = async (parent, node, _classes, isNode) => {
     bbox = div.getBoundingClientRect();
     dv.attr('width', bbox.width);
     dv.attr('height', bbox.height);
+    dv.style('height', bbox.height + 'px');
   }
 
   // Center the label
diff --git a/packages/mermaid/src/rendering-util/createText.ts b/packages/mermaid/src/rendering-util/createText.ts
index 462a4834f1..20625e7f4f 100644
--- a/packages/mermaid/src/rendering-util/createText.ts
+++ b/packages/mermaid/src/rendering-util/createText.ts
@@ -40,11 +40,14 @@ function addHtmlSpan(element, node, width, classes, addBackground = false) {
     div.style('display', 'table');
     div.style('white-space', 'break-spaces');
     div.style('width', width + 'px');
-    bbox = div.node().getBoundingClientRect();
+    const newBbox = div.node().getBoundingClientRect();
+    if (newBbox.height > 0) {
+      bbox = newBbox;
+    }
   }
 
-  fo.style('width', bbox.width);
-  fo.style('height', bbox.height);
+  fo.style('width', bbox.width + 'px');
+  fo.style('height', bbox.height + 'px');
 
   return fo.node();
 }