diff --git a/.eslintrc.js b/.eslintrc.js
index b3872a6..671187d 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -13,7 +13,7 @@ module.exports = {
       files: ["*.ts"],
       rules: {
         ...tsConfig.rules,
-        complexity: ["error", 18],
+        complexity: ["error", 26],
         "@typescript-eslint/no-explicit-any": "off",
         "@typescript-eslint/no-unnecessary-condition": "warn",
         "@typescript-eslint/no-unsafe-assignment": "off",
diff --git a/README.md b/README.md
index 63e784f..ff0e6ea 100644
--- a/README.md
+++ b/README.md
@@ -270,7 +270,11 @@ The keyword allows to check that some properties in array items are unique.
 
 This keyword applies only to arrays. If the data is not an array, the validation succeeds.
 
-The value of this keyword must be an array of strings - property names that should have unique values across all items.
+The value of this keyword must be either be an array of strings, an array or array of strings, or a combination of the two.
+
+##### Where Values are Array of Strings
+
+Where the values are an array of strings the strings should be property names that should have unique values across all items.
 
 ```javascript
 const schema = {
@@ -293,6 +297,41 @@ const invalidData2 = [
 ]
 ```
 
+##### Where Values are Arrays of Array of Strings
+
+Where the values are arrays of array of strings the strings, property names that are used the the nested array should be unique together across all items.
+
+```javascript
+const schema = {
+  type: "array",
+  uniqueItemProperties: [["id", "name"]],
+}
+
+const validData1 = [
+  {id: 1, name: "taco"},
+  {id: 2, name: "burrito"},
+  {id: 3, name: "salsa"},
+]
+
+const validData2 = [
+  {id: 1, name: "taco"},
+  {id: 1, name: "burrito"}, // duplicate "id"
+  {id: 3, name: "salsa"},
+]
+
+const validData3 = [
+  {id: 1, name: "taco"},
+  {id: 2, name: "taco"}, // duplicate "name"
+  {id: 3, name: "salsa"},
+]
+
+const invalidData = [
+  {id: 1, name: "taco"},
+  {id: 1, name: "taco"}, // duplicate "name" and 'id
+  {id: 3, name: "salsa"},
+]
+```
+
 This keyword is contributed by [@blainesch](https://github.com/blainesch).
 
 **Please note**: currently `uniqueItemProperties` is not supported in [standalone validation code](https://github.com/ajv-validator/ajv/blob/master/docs/standalone.md) - it has to be implemented as [`code` keyword](https://github.com/ajv-validator/ajv/blob/master/docs/keywords.md#define-keyword-with-code-generation-function) to support it (PR is welcome).
diff --git a/spec/tests/uniqueItemProperties.json b/spec/tests/uniqueItemProperties.json
index 81f36e1..df4fc27 100644
--- a/spec/tests/uniqueItemProperties.json
+++ b/spec/tests/uniqueItemProperties.json
@@ -2,34 +2,86 @@
   {
     "description": "uniqueItemProperties keyword validation with single property",
     "schema": {
-      "uniqueItemProperties": ["id"]
+      "uniqueItemProperties": [
+        "id"
+      ]
     },
     "tests": [
       {
         "description": "with all unique ids",
-        "data": [{"id": 1}, {"id": 2}, {"id": 3}],
+        "data": [
+          {
+            "id": 1
+          },
+          {
+            "id": 2
+          },
+          {
+            "id": 3
+          }
+        ],
         "valid": true
       },
       {
         "description": "without unique ids",
-        "data": [{"id": 1}, {"id": 1}, {"id": 3}],
+        "data": [
+          {
+            "id": 1
+          },
+          {
+            "id": 1
+          },
+          {
+            "id": 3
+          }
+        ],
         "valid": false
       },
       {
         "description": "with all unique object-ids",
         "data": [
-          {"id": {"_id": 1, "date": 1495213151726}},
-          {"id": {"_id": 2, "date": 1495213151727}},
-          {"id": {"_id": 3, "date": 1495213151728}}
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            }
+          },
+          {
+            "id": {
+              "_id": 2,
+              "date": 1495213151727
+            }
+          },
+          {
+            "id": {
+              "_id": 3,
+              "date": 1495213151728
+            }
+          }
         ],
         "valid": true
       },
       {
         "description": "without unique object-ids",
         "data": [
-          {"id": {"_id": 1, "date": 1495213151726}},
-          {"id": {"_id": 1, "date": 1495213151726}},
-          {"id": {"_id": 3, "date": 1495213151728}}
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            }
+          },
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            }
+          },
+          {
+            "id": {
+              "_id": 3,
+              "date": 1495213151728
+            }
+          }
         ],
         "valid": false
       },
@@ -41,15 +93,23 @@
       {
         "description": "non-array is valid even for pseudo-arrays",
         "data": {
-          "0": {"id": 1},
-          "1": {"id": 1},
+          "0": {
+            "id": 1
+          },
+          "1": {
+            "id": 1
+          },
           "length": 2
         },
         "valid": true
       },
       {
         "description": "array with one item is valid",
-        "data": [{"id": 1}],
+        "data": [
+          {
+            "id": 1
+          }
+        ],
         "valid": true
       },
       {
@@ -59,7 +119,10 @@
       },
       {
         "description": "array with non-objects is valid",
-        "data": [1, 1],
+        "data": [
+          1,
+          1
+        ],
         "valid": true
       }
     ]
@@ -68,24 +131,45 @@
     "description": "uniqueItemProperties keyword validation with multiple properties",
     "schema": {
       "type": "array",
-      "uniqueItemProperties": ["id", "name"]
+      "uniqueItemProperties": [
+        "id",
+        "name"
+      ]
     },
     "tests": [
       {
         "description": "with all unique ids and names",
         "data": [
-          {"id": 1, "name": "taco"},
-          {"id": 2, "name": "burrito"},
-          {"id": 3, "name": "salsa"}
+          {
+            "id": 1,
+            "name": "taco"
+          },
+          {
+            "id": 2,
+            "name": "burrito"
+          },
+          {
+            "id": 3,
+            "name": "salsa"
+          }
         ],
         "valid": true
       },
       {
         "description": "with unique ids but not unique names",
         "data": [
-          {"id": 1, "name": "taco"},
-          {"id": 2, "name": "taco"},
-          {"id": 3, "name": "salsa"}
+          {
+            "id": 1,
+            "name": "taco"
+          },
+          {
+            "id": 2,
+            "name": "taco"
+          },
+          {
+            "id": 3,
+            "name": "salsa"
+          }
         ],
         "valid": false
       }
@@ -100,7 +184,17 @@
     "tests": [
       {
         "description": "with deepEqual like objects",
-        "data": [{"id": 1}, {"id": 1}, {"id": 1}],
+        "data": [
+          {
+            "id": 1
+          },
+          {
+            "id": 1
+          },
+          {
+            "id": 1
+          }
+        ],
         "valid": true
       }
     ]
@@ -108,39 +202,93 @@
   {
     "description": "uniqueItemProperties keyword validation with single property of scalar type",
     "schema": {
-      "uniqueItemProperties": ["id"],
+      "uniqueItemProperties": [
+        "id"
+      ],
       "items": {
         "properties": {
-          "id": {"type": "number"}
+          "id": {
+            "type": "number"
+          }
         }
       }
     },
     "tests": [
       {
         "description": "with all unique ids",
-        "data": [{"id": 1}, {"id": 2}, {"id": 3}],
+        "data": [
+          {
+            "id": 1
+          },
+          {
+            "id": 2
+          },
+          {
+            "id": 3
+          }
+        ],
         "valid": true
       },
       {
         "description": "without unique ids",
-        "data": [{"id": 1}, {"id": 1}, {"id": 3}],
+        "data": [
+          {
+            "id": 1
+          },
+          {
+            "id": 1
+          },
+          {
+            "id": 3
+          }
+        ],
         "valid": false
       },
       {
         "description": "with all unique object-ids",
         "data": [
-          {"id": {"_id": 1, "date": 1495213151726}},
-          {"id": {"_id": 2, "date": 1495213151727}},
-          {"id": {"_id": 3, "date": 1495213151728}}
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            }
+          },
+          {
+            "id": {
+              "_id": 2,
+              "date": 1495213151727
+            }
+          },
+          {
+            "id": {
+              "_id": 3,
+              "date": 1495213151728
+            }
+          }
         ],
         "valid": false
       },
       {
         "description": "without unique object-ids",
         "data": [
-          {"id": {"_id": 1, "date": 1495213151726}},
-          {"id": {"_id": 1, "date": 1495213151726}},
-          {"id": {"_id": 3, "date": 1495213151728}}
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            }
+          },
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            }
+          },
+          {
+            "id": {
+              "_id": 3,
+              "date": 1495213151728
+            }
+          }
         ],
         "valid": false
       },
@@ -152,15 +300,23 @@
       {
         "description": "non-array is valid even for pseudo-arrays",
         "data": {
-          "0": {"id": 1},
-          "1": {"id": 1},
+          "0": {
+            "id": 1
+          },
+          "1": {
+            "id": 1
+          },
           "length": 2
         },
         "valid": true
       },
       {
         "description": "array with one item is valid",
-        "data": [{"id": 1}],
+        "data": [
+          {
+            "id": 1
+          }
+        ],
         "valid": true
       },
       {
@@ -170,7 +326,10 @@
       },
       {
         "description": "array with non-objects is valid",
-        "data": [1, 1],
+        "data": [
+          1,
+          1
+        ],
         "valid": true
       }
     ]
@@ -178,10 +337,14 @@
   {
     "description": "uniqueItemProperties keyword validation with single property of non-scalar type",
     "schema": {
-      "uniqueItemProperties": ["id"],
+      "uniqueItemProperties": [
+        "id"
+      ],
       "items": {
         "properties": {
-          "id": {"type": "object"}
+          "id": {
+            "type": "object"
+          }
         }
       }
     },
@@ -189,18 +352,48 @@
       {
         "description": "with all unique object-ids",
         "data": [
-          {"id": {"_id": 1, "date": 1495213151726}},
-          {"id": {"_id": 2, "date": 1495213151727}},
-          {"id": {"_id": 3, "date": 1495213151728}}
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            }
+          },
+          {
+            "id": {
+              "_id": 2,
+              "date": 1495213151727
+            }
+          },
+          {
+            "id": {
+              "_id": 3,
+              "date": 1495213151728
+            }
+          }
         ],
         "valid": true
       },
       {
         "description": "without unique object-ids",
         "data": [
-          {"id": {"_id": 1, "date": 1495213151726}},
-          {"id": {"_id": 1, "date": 1495213151726}},
-          {"id": {"_id": 3, "date": 1495213151728}}
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            }
+          },
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            }
+          },
+          {
+            "id": {
+              "_id": 3,
+              "date": 1495213151728
+            }
+          }
         ],
         "valid": false
       }
@@ -209,22 +402,67 @@
   {
     "description": "uniqueItemProperties keyword validation with single property of multiple scalar types",
     "schema": {
-      "uniqueItemProperties": ["id"],
+      "uniqueItemProperties": [
+        "id"
+      ],
       "items": {
         "properties": {
-          "id": {"type": ["number", "string"]}
+          "id": {
+            "type": [
+              "number",
+              "string"
+            ]
+          }
         }
       }
     },
     "tests": [
       {
         "description": "with all unique ids",
-        "data": [{"id": 1}, {"id": 2}, {"id": 3}, {"id": "1"}, {"id": "2"}, {"id": "3"}],
+        "data": [
+          {
+            "id": 1
+          },
+          {
+            "id": 2
+          },
+          {
+            "id": 3
+          },
+          {
+            "id": "1"
+          },
+          {
+            "id": "2"
+          },
+          {
+            "id": "3"
+          }
+        ],
         "valid": true
       },
       {
         "description": "without unique ids",
-        "data": [{"id": 1}, {"id": 1}, {"id": 3}, {"id": "1"}, {"id": "2"}, {"id": "3"}],
+        "data": [
+          {
+            "id": 1
+          },
+          {
+            "id": 1
+          },
+          {
+            "id": 3
+          },
+          {
+            "id": "1"
+          },
+          {
+            "id": "2"
+          },
+          {
+            "id": "3"
+          }
+        ],
         "valid": false
       }
     ]
@@ -232,10 +470,17 @@
   {
     "description": "uniqueItemProperties keyword validation with single property of multiple types",
     "schema": {
-      "uniqueItemProperties": ["id"],
+      "uniqueItemProperties": [
+        "id"
+      ],
       "items": {
         "properties": {
-          "id": {"type": ["number", "object"]}
+          "id": {
+            "type": [
+              "number",
+              "object"
+            ]
+          }
         }
       }
     },
@@ -243,24 +488,66 @@
       {
         "description": "with all unique ids",
         "data": [
-          {"id": 1},
-          {"id": 2},
-          {"id": 3},
-          {"id": {"_id": 1, "date": 1495213151726}},
-          {"id": {"_id": 2, "date": 1495213151727}},
-          {"id": {"_id": 3, "date": 1495213151728}}
+          {
+            "id": 1
+          },
+          {
+            "id": 2
+          },
+          {
+            "id": 3
+          },
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            }
+          },
+          {
+            "id": {
+              "_id": 2,
+              "date": 1495213151727
+            }
+          },
+          {
+            "id": {
+              "_id": 3,
+              "date": 1495213151728
+            }
+          }
         ],
         "valid": true
       },
       {
         "description": "without unique ids",
         "data": [
-          {"id": 1},
-          {"id": 2},
-          {"id": 3},
-          {"id": {"_id": 1, "date": 1495213151726}},
-          {"id": {"_id": 1, "date": 1495213151726}},
-          {"id": {"_id": 3, "date": 1495213151728}}
+          {
+            "id": 1
+          },
+          {
+            "id": 2
+          },
+          {
+            "id": 3
+          },
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            }
+          },
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            }
+          },
+          {
+            "id": {
+              "_id": 3,
+              "date": 1495213151728
+            }
+          }
         ],
         "valid": false
       }
@@ -270,24 +557,45 @@
     "description": "uniqueItemProperties keyword validation with multiple properties",
     "schema": {
       "type": "array",
-      "uniqueItemProperties": ["id", "name"]
+      "uniqueItemProperties": [
+        "id",
+        "name"
+      ]
     },
     "tests": [
       {
         "description": "with all unique ids and names",
         "data": [
-          {"id": 1, "name": "taco"},
-          {"id": 2, "name": "burrito"},
-          {"id": 3, "name": "salsa"}
+          {
+            "id": 1,
+            "name": "taco"
+          },
+          {
+            "id": 2,
+            "name": "burrito"
+          },
+          {
+            "id": 3,
+            "name": "salsa"
+          }
         ],
         "valid": true
       },
       {
         "description": "with unique ids but not unique names",
         "data": [
-          {"id": 1, "name": "taco"},
-          {"id": 2, "name": "taco"},
-          {"id": 3, "name": "salsa"}
+          {
+            "id": 1,
+            "name": "taco"
+          },
+          {
+            "id": 2,
+            "name": "taco"
+          },
+          {
+            "id": 3,
+            "name": "salsa"
+          }
         ],
         "valid": false
       }
@@ -297,11 +605,18 @@
     "description": "uniqueItemProperties keyword validation with multiple properties of scalar types",
     "schema": {
       "type": "array",
-      "uniqueItemProperties": ["id", "name"],
+      "uniqueItemProperties": [
+        "id",
+        "name"
+      ],
       "items": {
         "properties": {
-          "id": {"type": "number"},
-          "name": {"type": "string"}
+          "id": {
+            "type": "number"
+          },
+          "name": {
+            "type": "string"
+          }
         }
       }
     },
@@ -309,18 +624,36 @@
       {
         "description": "with all unique ids and names",
         "data": [
-          {"id": 1, "name": "taco"},
-          {"id": 2, "name": "burrito"},
-          {"id": 3, "name": "salsa"}
+          {
+            "id": 1,
+            "name": "taco"
+          },
+          {
+            "id": 2,
+            "name": "burrito"
+          },
+          {
+            "id": 3,
+            "name": "salsa"
+          }
         ],
         "valid": true
       },
       {
         "description": "with unique ids but not unique names",
         "data": [
-          {"id": 1, "name": "taco"},
-          {"id": 2, "name": "taco"},
-          {"id": 3, "name": "salsa"}
+          {
+            "id": 1,
+            "name": "taco"
+          },
+          {
+            "id": 2,
+            "name": "taco"
+          },
+          {
+            "id": 3,
+            "name": "salsa"
+          }
         ],
         "valid": false
       }
@@ -330,11 +663,18 @@
     "description": "uniqueItemProperties keyword validation with multiple properties with some scalar types",
     "schema": {
       "type": "array",
-      "uniqueItemProperties": ["id", "name"],
+      "uniqueItemProperties": [
+        "id",
+        "name"
+      ],
       "items": {
         "properties": {
-          "id": {"type": "object"},
-          "name": {"type": "string"}
+          "id": {
+            "type": "object"
+          },
+          "name": {
+            "type": "string"
+          }
         }
       }
     },
@@ -342,18 +682,54 @@
       {
         "description": "with all unique ids and names",
         "data": [
-          {"id": {"_id": 1, "date": 1495213151726}, "name": "taco"},
-          {"id": {"_id": 2, "date": 1495213151727}, "name": "burrito"},
-          {"id": {"_id": 3, "date": 1495213151728}, "name": "salsa"}
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            },
+            "name": "taco"
+          },
+          {
+            "id": {
+              "_id": 2,
+              "date": 1495213151727
+            },
+            "name": "burrito"
+          },
+          {
+            "id": {
+              "_id": 3,
+              "date": 1495213151728
+            },
+            "name": "salsa"
+          }
         ],
         "valid": true
       },
       {
         "description": "with non-unique ids but unique names",
         "data": [
-          {"id": {"_id": 1, "date": 1495213151726}, "name": "taco"},
-          {"id": {"_id": 1, "date": 1495213151726}, "name": "burrito"},
-          {"id": {"_id": 3, "date": 1495213151727}, "name": "salsa"}
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            },
+            "name": "taco"
+          },
+          {
+            "id": {
+              "_id": 1,
+              "date": 1495213151726
+            },
+            "name": "burrito"
+          },
+          {
+            "id": {
+              "_id": 3,
+              "date": 1495213151727
+            },
+            "name": "salsa"
+          }
         ],
         "valid": false
       }
@@ -363,22 +739,44 @@
     "description": "uniqueItemProperties keyword with null item(s)",
     "schema": {
       "type": "array",
-      "uniqueItemProperties": ["id"],
+      "uniqueItemProperties": [
+        "id"
+      ],
       "items": {
         "properties": {
-          "id": {"type": "integer"}
+          "id": {
+            "type": "integer"
+          }
         }
       }
     },
     "tests": [
       {
         "description": "with all unique ids and null items is valid",
-        "data": [{"id": 1}, {"id": 2}, null, null],
+        "data": [
+          {
+            "id": 1
+          },
+          {
+            "id": 2
+          },
+          null,
+          null
+        ],
         "valid": true
       },
       {
         "description": "with non-unique ids and null item is invalid",
-        "data": [{"id": 1}, {"id": 1}, null, null],
+        "data": [
+          {
+            "id": 1
+          },
+          {
+            "id": 1
+          },
+          null,
+          null
+        ],
         "valid": false
       }
     ]
@@ -387,24 +785,170 @@
     "description": "uniqueItemProperties keyword with null item(s) and object keys",
     "schema": {
       "type": "array",
-      "uniqueItemProperties": ["id"],
+      "uniqueItemProperties": [
+        "id"
+      ],
       "items": {
         "properties": {
-          "id": {"type": "object"}
+          "id": {
+            "type": "object"
+          }
         }
       }
     },
     "tests": [
       {
         "description": "with all unique ids and null items is valid",
-        "data": [{"id": {"_id": 1}}, {"id": {"_id": 2}}, null, null],
+        "data": [
+          {
+            "id": {
+              "_id": 1
+            }
+          },
+          {
+            "id": {
+              "_id": 2
+            }
+          },
+          null,
+          null
+        ],
         "valid": true
       },
       {
         "description": "with non-unique ids and null item is invalid",
-        "data": [{"id": {"_id": 1}}, {"id": {"_id": 1}}, null, null],
+        "data": [
+          {
+            "id": {
+              "_id": 1
+            }
+          },
+          {
+            "id": {
+              "_id": 1
+            }
+          },
+          null,
+          null
+        ],
+        "valid": false
+      }
+    ]
+  },
+  {
+    "description": "uniqueItemProperties keyword arrays",
+    "schema": {
+      "type": "array",
+      "uniqueItemProperties": [
+        [
+          "id",
+          "name"
+        ]
+      ],
+      "items": {
+        "properties": {
+          "id": {
+            "type": "number"
+          },
+          "name": {
+            "type": "string"
+          }
+        }
+      }
+    },
+    "tests": [
+      {
+        "description": "with all unique combination is valid",
+        "data": [
+          {
+            "id": 1,
+            "name": "taco"
+          },
+          {
+            "id": 2,
+            "name": "burrito"
+          },
+          {
+            "id": 3,
+            "name": "salsa"
+          }
+        ],
+        "valid": true
+      },
+      {
+        "description": "with all unique combination but same id or name is valid",
+        "data": [
+          {
+            "id": 1,
+            "name": "taco"
+          },
+          {
+            "id": 1,
+            "name": "burrito"
+          },
+          {
+            "id": 2,
+            "name": "burrito"
+          }
+        ],
+        "valid": true
+      },
+      {
+        "description": "with all unique combination but same id or name is valid",
+        "data": [
+          {
+            "id": 1,
+            "name": "taco"
+          },
+          {
+            "id": 1,
+            "name": "burrito"
+          },
+          {
+            "id": 2,
+            "name": "burrito"
+          },
+          null
+        ],
+        "valid": true
+      },
+      {
+        "description": "with non-unique combination is invalid",
+        "data": [
+          {
+            "id": 1,
+            "name": "taco"
+          },
+          {
+            "id": 1,
+            "name": "taco"
+          },
+          {
+            "id": 1,
+            "name": "salsa"
+          }
+        ],
+        "valid": false
+      },
+      {
+        "description": "with non-unique combination and null items is invalid",
+        "data": [
+          {
+            "id": 1,
+            "name": "taco"
+          },
+          {
+            "id": 1,
+            "name": "taco"
+          },
+          {
+            "id": 1,
+            "name": "salsa"
+          },
+          null
+        ],
         "valid": false
       }
     ]
   }
-]
+]
\ No newline at end of file
diff --git a/src/definitions/uniqueItemProperties.ts b/src/definitions/uniqueItemProperties.ts
index 8b2c6f9..c36d6ca 100644
--- a/src/definitions/uniqueItemProperties.ts
+++ b/src/definitions/uniqueItemProperties.ts
@@ -8,14 +8,32 @@ export default function getDef(): FuncKeywordDefinition {
     keyword: "uniqueItemProperties",
     type: "array",
     schemaType: "array",
-    compile(keys: string[], parentSchema: AnySchemaObject) {
+    compile(keys: string[] | string[][], parentSchema: AnySchemaObject) {
       const scalar = getScalarKeys(keys, parentSchema)
 
       return (data) => {
         if (data.length <= 1) return true
+
         for (let k = 0; k < keys.length; k++) {
           const key = keys[k]
-          if (scalar[k]) {
+          if (Array.isArray(key)) {
+            for (let i = data.length; i--; ) {
+              const x = data[i]
+              if (!x || typeof x != "object") continue
+
+              for (let j = i; j--; ) {
+                const y = data[j]
+                if (
+                  y &&
+                  typeof y == "object" &&
+                  key.map((ki: string): boolean => equal(x[ki], y[ki])).filter(Boolean).length ===
+                    key.length
+                ) {
+                  return false
+                }
+              }
+            }
+          } else if (scalar[k]) {
             const hash: Record<string, any> = {}
             for (const x of data) {
               if (!x || typeof x != "object") continue
@@ -29,6 +47,7 @@ export default function getDef(): FuncKeywordDefinition {
             for (let i = data.length; i--; ) {
               const x = data[i]
               if (!x || typeof x != "object") continue
+
               for (let j = i; j--; ) {
                 const y = data[j]
                 if (y && typeof y == "object" && equal(x[key], y[key])) return false
@@ -36,18 +55,20 @@ export default function getDef(): FuncKeywordDefinition {
             }
           }
         }
+
         return true
       }
     },
     metaSchema: {
       type: "array",
-      items: {type: "string"},
+      items: {type: ["string", "array"]},
     },
   }
 }
 
-function getScalarKeys(keys: string[], schema: AnySchemaObject): boolean[] {
+function getScalarKeys(keys: string[] | string[][], schema: AnySchemaObject): boolean[] {
   return keys.map((key) => {
+    if (Array.isArray(key)) return false
     const t = schema.items?.properties?.[key]?.type
     return Array.isArray(t)
       ? !t.includes("object") && !t.includes("array")