diff --git a/CHANGELOG.md b/CHANGELOG.md
index f21719ae8e..e832e4f5ac 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,11 @@ _Note: Gaps between patch versions are faulty/broken releases._
 
 See [CHANGELOG - 6to5](CHANGELOG-6to5.md) for the pre-4.0.0 version changelog.
 
+## 5.1.1
+
+ * **Bug Fix**
+  * Add missing runtime symbol definitions.
+
 ## 5.1.0
 
  * **Bug Fix**
diff --git a/src/babel/transformation/transformers/other/runtime/definitions.json b/src/babel/transformation/transformers/other/runtime/definitions.json
index 2476f8e16d..c2062fae06 100644
--- a/src/babel/transformation/transformers/other/runtime/definitions.json
+++ b/src/babel/transformation/transformers/other/runtime/definitions.json
@@ -7,6 +7,7 @@
     "Set": "set",
     "WeakSet": "weak-set"
   },
+
   "methods": {
     "Array": {
       "concat": "array/concat",
@@ -94,6 +95,21 @@
       "addLocale": "date/add-locale",
       "formatUTC": "date/format-utc",
       "format": "date/format"
+    },
+    "Symbol": {
+      "for": "symbol/for",
+      "hasInstance": "symbol/for-instance",
+      "is-concat-spreadable": "symbol/is-concat-spreadable",
+      "iterator": "symbol/iterator",
+      "keyFor": "symbol/key-for",
+      "match": "symbol/match",
+      "replace": "symbol/replace",
+      "search": "symbol/search",
+      "species": "symbol/species",
+      "split": "symbol/split",
+      "toPrimitive": "symbol/to-primitive",
+      "toStringTag": "symbol/to-string-tag",
+      "unscopables": "symbol/unscopables"
     }
   }
 }
diff --git a/test/core/fixtures/transformation/runtime/symbol-iterator/actual.js b/test/core/fixtures/transformation/runtime/symbol-iterator/actual.js
new file mode 100644
index 0000000000..ae1f0b9df5
--- /dev/null
+++ b/test/core/fixtures/transformation/runtime/symbol-iterator/actual.js
@@ -0,0 +1 @@
+Symbol.iterator;
diff --git a/test/core/fixtures/transformation/runtime/symbol-iterator/expected.js b/test/core/fixtures/transformation/runtime/symbol-iterator/expected.js
new file mode 100644
index 0000000000..70f3b80f57
--- /dev/null
+++ b/test/core/fixtures/transformation/runtime/symbol-iterator/expected.js
@@ -0,0 +1,5 @@
+"use strict";
+
+var _Symbol$iterator = require("babel-runtime/core-js/symbol/iterator")["default"];
+
+_Symbol$iterator;