diff --git a/packages/mermaid/src/diagrams/flowchart/flowDb.ts b/packages/mermaid/src/diagrams/flowchart/flowDb.ts
index db43ecaae..8d8245e67 100644
--- a/packages/mermaid/src/diagrams/flowchart/flowDb.ts
+++ b/packages/mermaid/src/diagrams/flowchart/flowDb.ts
@@ -161,11 +161,9 @@ export const addVertex = function (
       if (!doc.label?.trim() && vertex.text === id) {
         vertex.text = '';
       }
-      if (doc?.constraint) {
-        vertex.constraint = doc.constraint;
-      } else {
-        vertex.constraint = 'off';
-      }
+    }
+    if (doc?.constraint) {
+      vertex.constraint = doc.constraint;
     }
     if (doc.w) {
       vertex.assetWidth = Number(doc.w);
diff --git a/packages/mermaid/src/rendering-util/rendering-elements/shapes/imageSquare.ts b/packages/mermaid/src/rendering-util/rendering-elements/shapes/imageSquare.ts
index 9cd5da007..4306cfc17 100644
--- a/packages/mermaid/src/rendering-util/rendering-elements/shapes/imageSquare.ts
+++ b/packages/mermaid/src/rendering-util/rendering-elements/shapes/imageSquare.ts
@@ -26,10 +26,18 @@ export const imageSquare = async (
   const defaultWidth = flowchart?.wrappingWidth;
   node.defaultWidth = flowchart?.wrappingWidth;
 
-  const imageWidth = Math.max(
+  const imageRawWidth = Math.max(
     node.label ? (defaultWidth ?? 0) : 0,
     node?.assetWidth ?? imageNaturalWidth
   );
+
+  const imageWidth =
+    node.constraint === 'on'
+      ? node?.assetHeight
+        ? node.assetHeight * node.imageAspectRatio
+        : imageRawWidth
+      : imageRawWidth;
+
   const imageHeight =
     node.constraint === 'on'
       ? imageWidth / node.imageAspectRatio