diff --git a/src/signed-xml.ts b/src/signed-xml.ts
index 05dae41..a02f18a 100644
--- a/src/signed-xml.ts
+++ b/src/signed-xml.ts
@@ -1195,7 +1195,7 @@ export class SignedXml {
         id,
       );
     } else {
-      node.setAttribute("Id", id);
+      node.setAttribute(this.idAttributes[0], id);
     }
 
     return id;
diff --git a/test/signature-unit-tests.spec.ts b/test/signature-unit-tests.spec.ts
index baa382d..91ba051 100644
--- a/test/signature-unit-tests.spec.ts
+++ b/test/signature-unit-tests.spec.ts
@@ -17,9 +17,9 @@ describe("Signature unit tests", function () {
       expect(node.length, `xpath ${xpathArg} not found`).to.equal(1);
     }
 
-    function verifyAddsId(mode, nsMode) {
+    function verifyAddsId(mode, nsMode, idAttribute:string|undefined = undefined) {
       const xml = '<root><x xmlns="ns"></x><y attr="value"></y><z><w></w></z></root>';
-      const sig = new SignedXml({ idMode: mode });
+      const sig = new SignedXml({ idMode: mode, idAttribute });
       sig.privateKey = fs.readFileSync("./test/static/client.pem");
 
       sig.addReference({
@@ -46,7 +46,7 @@ describe("Signature unit tests", function () {
 
       const op = nsMode === "equal" ? "=" : "!=";
 
-      const xpathArg = `//*[local-name(.)='{elem}' and '_{id}' = @*[local-name(.)='Id' and namespace-uri(.)${op}'http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd']]`;
+      const xpathArg = `//*[local-name(.)='{elem}' and '_{id}' = @*[local-name(.)='${idAttribute || 'Id'}' and namespace-uri(.)${op}'http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd']]`;
 
       //verify each of the signed nodes now has an "Id" attribute with the right value
       nodeExists(doc, xpathArg.replace("{id}", "0").replace("{elem}", "x"));
@@ -54,6 +54,10 @@ describe("Signature unit tests", function () {
       nodeExists(doc, xpathArg.replace("{id}", "2").replace("{elem}", "w"));
     }
 
+    it("signer adds increasing different id attributes to elements with custom idAttribute", function () {
+      verifyAddsId(null, "different", 'myIdAttribute');
+    });
+
     it("signer adds increasing different id attributes to elements", function () {
       verifyAddsId(null, "different");
     });