diff --git a/src/routingHeader.ts b/src/routingHeader.ts
index 5938c01a5..d30027a73 100644
--- a/src/routingHeader.ts
+++ b/src/routingHeader.ts
@@ -29,6 +29,8 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+import * as querystring from 'querystring';
+
 /**
  * Helpers for constructing routing headers.
  *
@@ -44,8 +46,9 @@
  * @param {Object} params - the request header parameters.
  * @return {string} the routing header value.
  */
-export function fromParams(params: {[index: string]: {}}): string {
-  return Object.keys(params)
-    .map(key => `${key}=${params[key]}`)
-    .join('&');
+
+export function fromParams(params: {
+  [index: string]: string | number | boolean;
+}): string {
+  return querystring.stringify(params);
 }
diff --git a/test/routingHeader.ts b/test/routingHeader.ts
index a5a6d35ff..95e78c0ee 100644
--- a/test/routingHeader.ts
+++ b/test/routingHeader.ts
@@ -37,4 +37,11 @@ describe('fromParams', () => {
     const routingHeader = fromParams({name: 'foo', 'book.read': true});
     expect(routingHeader).to.equal('name=foo&book.read=true');
   });
+
+  it('encodes non-ASCII characters', () => {
+    const routingHeader = fromParams({screaming: '😱', cyrillic: 'тест'});
+    expect(routingHeader).to.equal(
+      'screaming=%F0%9F%98%B1&cyrillic=%D1%82%D0%B5%D1%81%D1%82'
+    );
+  });
 });