diff --git a/src/lib/default-transformer.js b/src/lib/default-transformer.js
index 8b25fe6..deab03d 100644
--- a/src/lib/default-transformer.js
+++ b/src/lib/default-transformer.js
@@ -20,9 +20,9 @@ export default function(input, {project, baseURI}) {
 
     // subjects in a specific project : @owner-slug/project-slug^subject_id
     // \b[\w-]+\b is hyphen boundary for slugs
-        .replace(/@(\b[\w-]+\b)\/(\b[\w-]+\b)\^([0-9]+)/g, `<a href="${baseURI}/projects/$1/$2/talk/subjects/$3">$1/$2 - Subject $3</a>`)
+        .replace(/@(\b[\w-]+\b)\/(\b[\w-]+\b)\^S([0-9]+)/g, `<a href="${baseURI}/projects/$1/$2/talk/subjects/$3">$1/$2 - Subject $3</a>`)
 
-        .replace(/\^([0-9]+)/g, function(_, subjectID) {
+        .replace(/\^S([0-9]+)/g, function(_, subjectID) {
             if (owner && name) {
                 return `<a href="${baseURI}/projects/${owner}/${name}/talk/subjects/${subjectID}">${owner}/${name} - Subject ${subjectID}</a>`;
             }
diff --git a/test/lib/default-transformer-test.js b/test/lib/default-transformer-test.js
index 2fdb58a..32ce411 100644
--- a/test/lib/default-transformer-test.js
+++ b/test/lib/default-transformer-test.js
@@ -25,19 +25,19 @@ describe('default-transformer', () => {
         expect(htmlTagLink).to.equal(`<p><a href="#/talk/search?query=good">#good</a> \n https://www.zooniverse.org/#/talk/17/1403?page=1&comment=3063</p>`);
     });
 
-    it('replaces ^subject mentions with subject links', () =>{
+    it('replaces ^S<subject_id> mentions with subject links', () =>{
         project = { slug: "test/project" };
-        var subjectLink = replaceSymbols('^123456', {project, baseURI});;
+        var subjectLink = replaceSymbols('^S123456', {project, baseURI});;
         expect(subjectLink).to.equal('<a href="#/projects/test/project/talk/subjects/123456">test/project - Subject 123456</a>');
     });
 
     it('does not format subject Ids when not in a routed context', () =>{
-        var subjectLink = replaceSymbols('^123456', {project, baseURI});
+        var subjectLink = replaceSymbols('^S123456', {project, baseURI});
         expect(subjectLink).to.equal("123456");
     });
 
-    it('replaces @ownerslug/project-slug^subject_id mentions with links', () => {
-        var projectSubjectLink = replaceSymbols('@owner/project-d^123456', {project, baseURI});
+    it('replaces @ownerslug/project-slug^S<subject_id> mentions with links', () => {
+        var projectSubjectLink = replaceSymbols('@owner/project-d^S123456', {project, baseURI});
 
         expect(projectSubjectLink).to.equal('<a href="#/projects/owner/project-d/talk/subjects/123456">owner/project-d - Subject 123456</a>');
     });