diff --git a/reana-ui/src/pages/launchOnReana/LaunchOnReana.js b/reana-ui/src/pages/launchOnReana/LaunchOnReana.js
index 8a7d391e..4e25010c 100644
--- a/reana-ui/src/pages/launchOnReana/LaunchOnReana.js
+++ b/reana-ui/src/pages/launchOnReana/LaunchOnReana.js
@@ -46,7 +46,12 @@ export default function LaunchOnReana() {
             // Iterate over all keys in validation_warning
             for (const key in validation_warnings) {
               if (key === "additional_properties") {
-                const properties = validation_warnings[key].join(", ");
+                const properties = validation_warnings[key]
+                  .map(
+                    (additionalProperty) =>
+                      `${additionalProperty.property} (at ${additionalProperty.path})`,
+                  )
+                  .join(", ");
                 warningMessages.push(
                   `Unexpected properties found in the REANA specification: ${properties}.`,
                 );