diff --git a/lib/SqlString.js b/lib/SqlString.js
index d4fb470..8c8a0a1 100644
--- a/lib/SqlString.js
+++ b/lib/SqlString.js
@@ -23,11 +23,13 @@ SqlString.escapeId = function escapeId(val, forbidQualified) {
     return sql;
   }
 
+  var stringified = (typeof val === 'string') ? val : String(val);
+
   if (forbidQualified) {
-    return '`' + val.replace(/`/g, '``') + '`';
+    return '`' + stringified.replace(/`/g, '``') + '`';
   }
 
-  return '`' + val.replace(/`/g, '``').replace(/\./g, '`.`') + '`';
+  return '`' + stringified.replace(/`/g, '``').replace(/\./g, '`.`') + '`';
 };
 
 SqlString.escape = function escape(val, stringifyObjects, timeZone) {
diff --git a/test/unit/test-SqlString.js b/test/unit/test-SqlString.js
index 044fcac..540c08b 100644
--- a/test/unit/test-SqlString.js
+++ b/test/unit/test-SqlString.js
@@ -27,6 +27,10 @@ test('SqlString.escapeId', {
 
   'nested arrays are flattened': function() {
     assert.equal(SqlString.escapeId(['a', ['b', ['t.c']]]), "`a`, `b`, `t`.`c`");
+  },
+
+  'number is escaped': function() {
+    assert.equal(SqlString.escapeId(1), '`1`');
   }
 });