diff --git a/javascript/src/iframe/viamapi-iframe.js b/javascript/src/iframe/viamapi-iframe.js
index 1b40b926163b0b6403cc9a159876b511aba5cd31..48147baf4552436864ec0880213713ffe66b24ea 100644
--- a/javascript/src/iframe/viamapi-iframe.js
+++ b/javascript/src/iframe/viamapi-iframe.js
@@ -1616,7 +1616,21 @@ const connection = Penpal.connectToParent({
       }
 
       const validationResult = validateVMimeResponse.data;
-      return encodeResponse("200", validationResult, "Validation result retrieved");
+      const {signatures} = validationResult;
+      if (signatures) {
+        for (const signature of signatures) {
+          const certificateChain = signature.certificateChainPEM.map((certificatePEM) => {
+            const certificate = parseCertificate(certificatePEM);
+            const certificateData = new CertificateData(certificate);
+            return certificateData;
+          });
+          signature.certificateChain = certificateChain;
+        }
+      }
+
+      const result = {...validationResult, signatures};
+
+      return encodeResponse("200", result, "Validation result retrieved");
     },
     generateQrCode,
     documentCreateDocument: async (passportUUID, path, contentType, title) => {