diff --git a/lib/core/uri_parser.js b/lib/core/uri_parser.js
index 0f51e0d72e..92c9a877b8 100644
--- a/lib/core/uri_parser.js
+++ b/lib/core/uri_parser.js
@@ -510,7 +510,7 @@ function assertTlsOptionsAreEqual(optionName, queryString, queryStringKeys) {
       const firstValue = queryString[optionName][0];
       queryString[optionName].forEach(tlsValue => {
         if (tlsValue !== firstValue) {
-          throw new MongoParseError('All values of ${optionName} must be the same.');
+          throw new MongoParseError(`All values of ${optionName} must be the same.`);
         }
       });
     }
diff --git a/test/unit/core/connection_string.test.js b/test/unit/core/connection_string.test.js
index 6e5c914216..f9f9cd31be 100644
--- a/test/unit/core/connection_string.test.js
+++ b/test/unit/core/connection_string.test.js
@@ -203,6 +203,13 @@ describe('Connection String', function() {
         done();
       });
     });
+
+    it('should validate non-equal tls values', function(done) {
+      parseConnectionString('mongodb://localhost/?tls=true&tls=false', err => {
+        expect(err).to.have.property('message', 'All values of tls must be the same.');
+        done();
+      });
+    });
   });
 
   describe('spec tests', function() {