diff --git a/lib/http/server.js b/lib/http/server.js
index 1fe7ece0..dd25cb2a 100644
--- a/lib/http/server.js
+++ b/lib/http/server.js
@@ -270,8 +270,7 @@ HTTPServer.prototype.initRouter = function initRouter() {
     var hash = valid.get('block');
     var block, view, height;
 
-    enforce(typeof hash === 'number' || typeof hash === 'string',
-      'Hash or height required.');
+    enforce(typeof hash === 'string', 'Hash or height required.');
     enforce(!this.chain.options.spv, 'Cannot get block in SPV mode.');
 
     if (hash.length === 64)