diff --git a/src/helpers-test.ts b/src/helpers-test.ts
new file mode 100644
index 000000000..4aac5ebec
--- /dev/null
+++ b/src/helpers-test.ts
@@ -0,0 +1,21 @@
+import {test, TestLib} from "testlib/talertest";
+import * as helpers from "./helpers";
+
+
+test("URL canonicalization", (t: TestLib) => {
+  // converts to relative, adds https
+  t.assertEqualsStrict(
+    "https://alice.example.com/exchange/",
+    helpers.canonicalizeBaseUrl("alice.example.com/exchange"))
+
+  // keeps http, adds trailing slash
+  t.assertEqualsStrict(
+    "http://alice.example.com/exchange/",
+    helpers.canonicalizeBaseUrl("http://alice.example.com/exchange"))
+
+  // keeps http, adds trailing slash
+  t.assertEqualsStrict(
+    "http://alice.example.com/exchange/",
+    helpers.canonicalizeBaseUrl("http://alice.example.com/exchange#foobar"))
+  t.pass();
+});
diff --git a/src/helpers.ts b/src/helpers.ts
index 26cd350ee..2e7a701c3 100644
--- a/src/helpers.ts
+++ b/src/helpers.ts
@@ -50,7 +50,7 @@ export function canonicalizeBaseUrl(url: string) {
     x.protocol("https");
   }
   x.path(x.path() + "/").normalizePath();
-  x.fragment();
+  x.fragment("");
   x.query();
   return x.href()
 }
diff --git a/testlib/selenium/testhost.html b/testlib/selenium/testhost.html
index fcc9394f2..01641547d 100644
--- a/testlib/selenium/testhost.html
+++ b/testlib/selenium/testhost.html
@@ -7,6 +7,8 @@
     <script src="/testlib/selenium/escodegen.browser.js"></script>
     <script src="/testlib/selenium/instrumenter.js"></script>
 
+    <script src="/src/vendor/URI.js"></script>
+
     <!-- for instrumentation to work, we have to use the non-csp version -->
     <script src="/testlib/selenium/system.js"></script>
 
diff --git a/testlib/talertest.ts b/testlib/talertest.ts
index 6012eb657..b602fca14 100644
--- a/testlib/talertest.ts
+++ b/testlib/talertest.ts
@@ -30,6 +30,7 @@ export interface TestLib {
   pass(msg?: string): void;
   fail(msg?: string): void;
   assert(v: any, msg?: string): void;
+  assertEqualsStrict(v1: any, v2: any, msg?: string): void;
 }
 
 let tests: Test[] = [];
@@ -75,8 +76,17 @@ export async function run(statusCallback?: (m: string) => void) {
           throw Error("test failed");
         }
       };
+      let assertEqualsStrict = (v1: any, v2: any, msg?: string) => {
+        if (v1 !== v2) {
+          console.log(`# expected: ${v1}`);
+          console.log(`# actual: ${v2}`);
+          lastMsg = msg;
+          reject();
+          throw Error("test failed");
+        }
+      };
       // Test might return a promise.  If so, wait for it.
-      let r = t.testFn({pass,fail, assert});
+      let r = t.testFn({pass,fail, assert, assertEqualsStrict});
       r.then(() => resolve(), (e) => reject(e));
     });
 
diff --git a/tsconfig.json b/tsconfig.json
index 4daa17fbb..54ec05ca8 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -23,8 +23,9 @@
     "src/emscriptif-test.ts",
     "src/cryptoApi.ts",
     "decl/react-global.d.ts",
-    "src/types-test.ts",
+    "src/helpers-test.ts",
     "src/cryptoLib.ts",
+    "src/types-test.ts",
     "decl/chrome/chrome.d.ts",
     "src/cryptoWorker.ts",
     "src/db.ts",