diff --git a/src/core/operations/DeriveDUKPTAESKey.mjs b/src/core/operations/DeriveDUKPTAESKey.mjs
index 737c55d9..8d798df9 100644
--- a/src/core/operations/DeriveDUKPTAESKey.mjs
+++ b/src/core/operations/DeriveDUKPTAESKey.mjs
@@ -305,8 +305,9 @@ class DeriveDUKPTAESKey extends Operation {
 
         if (deriveMode === "Initial Key (IK)") {
             if (outputJson) {
-                const out = { inputKeyType, ik: hex(ik) };
+                const out = { inputKeyType, ksn: hex(ksn), iki: hex(iki), counter: `0x${counter.toString(16).padStart(8, "0").toUpperCase()}` };
                 if (inputKeyType === "BDK") out.bdk = hex(inputKey);
+                out.ik = hex(ik);
                 return JSON.stringify(out, null, 4);
             }
             return hex(ik);
@@ -317,7 +318,7 @@ class DeriveDUKPTAESKey extends Operation {
         const wkKey  = deriveWorkingKey(txKey, iki, counter, purpose);
 
         if (outputJson) {
-            const out = { inputKeyType, iki: hex(iki), counter: `0x${counter.toString(16).padStart(8, "0").toUpperCase()}` };
+            const out = { inputKeyType, ksn: hex(ksn), iki: hex(iki), counter: `0x${counter.toString(16).padStart(8, "0").toUpperCase()}` };
             if (inputKeyType === "BDK") out.bdk = hex(inputKey);
             out.ik             = hex(ik);
             out.transactionKey = hex(txKey);
diff --git a/src/core/operations/DeriveDUKPTKey.mjs b/src/core/operations/DeriveDUKPTKey.mjs
index 20a54315..8f1ec8f2 100644
--- a/src/core/operations/DeriveDUKPTKey.mjs
+++ b/src/core/operations/DeriveDUKPTKey.mjs
@@ -253,9 +253,11 @@ class DeriveDUKPTKey extends Operation {
         const ipek = deriveIpek(bdk, ksn);
         const ipekHex = toHexFast(ipek).toUpperCase();
 
+        const ksnHexOut = toHexFast(ksn).toUpperCase();
+
         if (mode === "Derive IPEK") {
             if (outputJson) {
-                return JSON.stringify({ mode, ipek: ipekHex }, null, 4);
+                return JSON.stringify({ mode, ksn: ksnHexOut, bdk: toHexFast(bdk).toUpperCase(), ipek: ipekHex }, null, 4);
             }
             return ipekHex;
         }
@@ -267,6 +269,8 @@ class DeriveDUKPTKey extends Operation {
         if (outputJson) {
             return JSON.stringify({
                 mode,
+                ksn: ksnHexOut,
+                bdk: toHexFast(bdk).toUpperCase(),
                 ipek: ipekHex,
                 sessionBase: toHexFast(sessionBase).toUpperCase(),
                 variant,
diff --git a/tests/operations/tests/Payment.mjs b/tests/operations/tests/Payment.mjs
index a95d350a..b4a553f4 100644
--- a/tests/operations/tests/Payment.mjs
+++ b/tests/operations/tests/Payment.mjs
@@ -482,6 +482,8 @@ TestRegister.addTests([
         input: "0123456789ABCDEFFEDCBA9876543210",
         expectedOutput: JSON.stringify({
             mode: "Derive Session Key",
+            ksn: "FFFF9876543210E00001",
+            bdk: "0123456789ABCDEFFEDCBA9876543210",
             ipek: "6AC292FAA1315B4D858AB3A3D7D5933A",
             sessionBase: "042666B49184CFA368DE9628D0397BC9",
             variant: "None",