diff --git a/lib-es5/utils/index.js b/lib-es5/utils/index.js
index 6a5e59e2..5b0bd22c 100644
--- a/lib-es5/utils/index.js
+++ b/lib-es5/utils/index.js
@@ -347,16 +347,53 @@ function encode_key_value(arg) {
   }).join('|');
 }
 
-function encode_context(arg) {
-  if (!isObject(arg)) {
-    return arg;
+/**
+ * @description Escape = and | with two backslashes \\
+ * @param {string|number} value
+ * @return {string}
+ */
+function escapeMetadataValue(value) {
+  return value.toString().replace(/([=|])/g, '\\$&');
+}
+
+/**
+ *
+ * @description Encode metadata fields based on incoming value.
+ *              If array, escape as color_id=[\"green\",\"red\"]
+ *              If string/number, escape as in_stock_id=50
+ *
+ *              Joins resulting values with a pipe:
+ *              in_stock_id=50|color_id=[\"green\",\"red\"]
+ *
+ *              = and | and escaped by default (this can't be turned off)
+ *
+ * @param metadataObj
+ * @return {string}
+ */
+function encode_context(metadataObj) {
+  if (!isObject(metadataObj)) {
+    return metadataObj;
   }
-  return entries(arg).map(function (_ref3) {
-    var _ref4 = _slicedToArray(_ref3, 2),
-        k = _ref4[0],
-        v = _ref4[1];
 
-    return `${k}=${v.replace(/([=|])/g, '\\$&')}`;
+  return entries(metadataObj).map(function (_ref3) {
+    var _ref4 = _slicedToArray(_ref3, 2),
+        key = _ref4[0],
+        value = _ref4[1];
+
+    // if string, simply parse the value and move on
+    if (isString(value)) {
+      return `${key}=${escapeMetadataValue(value)}`;
+
+      // If array, parse each item individually
+    } else if (isArray(value)) {
+      var values = value.map(function (innerVal) {
+        return `\"${escapeMetadataValue(innerVal)}\"`;
+      }).join(',');
+      return `${key}=[${values}]`;
+      // if unknown, return the value as string
+    } else {
+      return value.toString();
+    }
   }).join('|');
 }
 
diff --git a/lib/utils/index.js b/lib/utils/index.js
index 940d7f84..d121c3c5 100644
--- a/lib/utils/index.js
+++ b/lib/utils/index.js
@@ -320,9 +320,50 @@ function encode_key_value(arg) {
   return entries(arg).map(([k, v]) => `${k}=${v}`).join('|');
 }
 
-function encode_context(arg) {
-  if (!isObject(arg)) { return arg; }
-  return entries(arg).map(([k, v]) => `${k}=${v.replace(/([=|])/g, '\\$&')}`).join('|');
+
+/**
+ * @description Escape = and | with two backslashes \\
+ * @param {string|number} value
+ * @return {string}
+ */
+function escapeMetadataValue(value) {
+  return value.toString().replace(/([=|])/g, '\\$&');
+}
+
+
+/**
+ *
+ * @description Encode metadata fields based on incoming value.
+ *              If array, escape as color_id=[\"green\",\"red\"]
+ *              If string/number, escape as in_stock_id=50
+ *
+ *              Joins resulting values with a pipe:
+ *              in_stock_id=50|color_id=[\"green\",\"red\"]
+ *
+ *              = and | and escaped by default (this can't be turned off)
+ *
+ * @param metadataObj
+ * @return {string}
+ */
+function encode_context(metadataObj) {
+  if (!isObject(metadataObj)) { return metadataObj; }
+
+  return entries(metadataObj).map(([key, value]) => {
+    // if string, simply parse the value and move on
+    if (isString(value)) {
+      return `${key}=${escapeMetadataValue(value)}`;
+
+      // If array, parse each item individually
+    } else if (isArray(value)) {
+      let values = value.map((innerVal) => {
+        return `\"${escapeMetadataValue(innerVal)}\"`
+      }).join(',');
+      return `${key}=[${values}]`
+      // if unknown, return the value as string
+    } else {
+      return value.toString();
+    }
+  }).join('|');
 }
 
 function build_eager(transformations) {
diff --git a/test/integration/api/admin/structured_metadata_spec.js b/test/integration/api/admin/structured_metadata_spec.js
index aaf50688..3dd5bafb 100644
--- a/test/integration/api/admin/structured_metadata_spec.js
+++ b/test/integration/api/admin/structured_metadata_spec.js
@@ -15,6 +15,7 @@ const EXTERNAL_ID_ENUM_2 = 'metadata_external_id_enum_2_' + TEST_ID;
 const EXTERNAL_ID_SET = 'metadata_external_id_set_' + TEST_ID;
 const EXTERNAL_ID_SET_2 = 'metadata_external_id_set_2_' + TEST_ID;
 const EXTERNAL_ID_SET_3 = 'metadata_external_id_set_3_' + TEST_ID;
+const EXTERNAL_ID_SET_4 = 'metadata_external_id_set_4_' + TEST_ID;
 const EXTERNAL_ID_DELETE = 'metadata_deletion_' + TEST_ID;
 const EXTERNAL_ID_DELETE_2 = 'metadata_deletion_2_' + TEST_ID;
 const EXTERNAL_ID_DATE_VALIDATION = 'metadata_date_validation_' + TEST_ID;
@@ -414,4 +415,29 @@ describe("structured metadata api", function () {
         });
     });
   });
+
+  it('Should update an metadata field that is an array', (done) => {
+    let metadata = {
+      "external_id": EXTERNAL_ID_SET_4,
+      "label": EXTERNAL_ID_SET_4,
+      "type": "set",
+      "datasource": {
+        "values": [
+          {
+            "external_id": "1",
+            "value": "Email",
+            "state": "active"
+          }
+        ]
+      }
+    };
+
+    api.add_metadata_field(metadata, (res, res2) => {
+      cloudinary.v2.uploader.update_metadata({[EXTERNAL_ID_SET_4]: [1]}, ['sample'], (err, res) => {
+        expect(typeof err).to.be('undefined');
+        expect(res.public_ids[0]).to.equal('sample');
+        done();
+      })
+    });
+  });
 });