diff --git a/lib/handlers/get.js b/lib/handlers/get.js
index f4aed8ee..a35924ea 100644
--- a/lib/handlers/get.js
+++ b/lib/handlers/get.js
@@ -116,10 +116,9 @@ async function handler (req, res, next) {
 
   // If it is not in our RDFs we can't even translate,
   // Sorry, we can't help
-  if (!possibleRDFType) {
+  if (!possibleRDFType || !RDFs.includes(contentType)) { // possibleRDFType defaults to text/turtle
     return next(error(406, 'Cannot serve requested type: ' + contentType))
   }
-
   try {
     // Translate from the contentType found to the possibleRDFType desired
     const data = await translate(stream, baseUri, contentType, possibleRDFType)
@@ -128,8 +127,8 @@ async function handler (req, res, next) {
     res.send(data)
     return next()
   } catch (err) {
-    debug('error translating: ' + req.originalUrl + ' ' + contentType + ' -> ' + possibleRDFType + ' -- ' + 500 + ' ' + err.message)
-    return next(error(500, 'Error translating between RDF formats'))
+    debug('error translating: ' + req.originalUrl + ' ' + contentType + ' -> ' + possibleRDFType + ' -- ' + 406 + ' ' + err.message)
+    return next(error(500, 'Cannot serve requested type: ' + requestedType))
   }
 }
 
diff --git a/test/integration/acl-oidc-test.js b/test/integration/acl-oidc-test.js
index 8df0aa3b..1de13539 100644
--- a/test/integration/acl-oidc-test.js
+++ b/test/integration/acl-oidc-test.js
@@ -775,12 +775,12 @@ describe('ACL with WebID+OIDC over HTTP', function () {
         done()
       })
     })
-    it('We should have a 500 with invalid group listings', function (done) {
+    it('We should have a 406 with invalid group listings', function (done) {
       const options = createOptions('/group/test-folder/some-other-file.txt', 'user2')
 
       request.get(options, function (error, response, body) {
         assert.equal(error, null)
-        assert.equal(response.statusCode, 500)
+        assert.equal(response.statusCode, 406)
         done()
       })
     })
diff --git a/test/integration/formats-test.js b/test/integration/formats-test.js
index 0fa43a60..4a8ef11b 100644
--- a/test/integration/formats-test.js
+++ b/test/integration/formats-test.js
@@ -108,6 +108,21 @@ describe('formats', function () {
     })
   })
 
+  describe('text/plain (non RDFs)', function () {
+    it('Accept text/plain', function (done) {
+      server.get('/put-input.txt')
+        .set('accept', 'text/plain')
+        .expect('Content-type', 'text/plain')
+        .expect(200, done)
+    })
+    it('Accept text/turtle', function (done) {
+      server.get('/put-input.txt')
+        .set('accept', 'text/turtle')
+        .expect('Content-type', 'text/plain; charset=utf-8')
+        .expect(406, done)
+    })
+  })
+
   describe('none', function () {
     it('should return turtle document if no Accept header is set', function (done) {
       server.get('/patch-5-initial.ttl')