diff --git a/CHANGELOG.md b/CHANGELOG.md
index 81c6920..7840d89 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 4.8.0
+
+* Reject MBTiles with duplicate `id` fields in the json vector_layers metadata array [#104](https://github.com/mapbox/mapbox-upload-validate/pull/104)
+
 ## 4.7.0
 
 * Require mbtiles metadata maxzoom to match the tiles table maxzoom
diff --git a/lib/validators/mbtiles.js b/lib/validators/mbtiles.js
index 3e7def6..201b615 100644
--- a/lib/validators/mbtiles.js
+++ b/lib/validators/mbtiles.js
@@ -53,8 +53,17 @@ function validFormat(db, info, callback) {
     var format = tiletype.type(result.tile_data);
     if (!format) return callback(invalid('Unknown format.'));
 
-    if (format === 'pbf' && !info.hasOwnProperty('vector_layers'))
-      return callback(invalid('Vector source must include "vector_layers" key'));
+    if (format === 'pbf') {
+      if (!info.hasOwnProperty('vector_layers')) return callback(invalid('Vector source must include "vector_layers" key'));
+
+      // disallow duplicate layers by ID
+      var ids = [];
+      for (var i = 0; i < info.vector_layers.length; i++) {
+        var id = info.vector_layers[i].id;
+        if (ids.includes(id)) return callback(invalid('Vector source "vector_layers" contains duplicate ID: ' + id));
+        ids.push(info.vector_layers[i].id);
+      }
+    }
 
     log.debug('validFormat(): valid!');
     callback();
@@ -109,7 +118,7 @@ function zoomCheck(db, limits, callback) {
       cb(null, result);
     });
   }
-  
+
   log.debug('zoomCheck(): checking...');
   queue()
     .defer(getMaxZoom, 'tiles_max')
diff --git a/package-lock.json b/package-lock.json
index 3ce8c6c..10b317a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "@mapbox/mapbox-upload-validate",
-  "version": "4.7.0",
+  "version": "4.8.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -32,7 +32,7 @@
     "@mapbox/mapbox-file-sniff": {
       "version": "1.0.4",
       "resolved": "https://registry.npmjs.org/@mapbox/mapbox-file-sniff/-/mapbox-file-sniff-1.0.4.tgz",
-      "integrity": "sha1-h56x80K5l7Fk0nShDis9616jako=",
+      "integrity": "sha512-kZ9eK5IIyaqwbh9C1ccJ6B1CYAojA3LG+OHlThs5cq1fgh+W7pnPAjkK41r4YvwHwqEeUhCwGiajEk1+gsdI0Q==",
       "requires": {
         "@mapbox/detect-geocsv": "0.1.0",
         "buffer": "^3.2.2",
@@ -56,7 +56,7 @@
     "@mapbox/mbtiles": {
       "version": "0.10.0",
       "resolved": "https://registry.npmjs.org/@mapbox/mbtiles/-/mbtiles-0.10.0.tgz",
-      "integrity": "sha1-YwVJ6Osj4zxBLeS/S/i2Bdo4xr0=",
+      "integrity": "sha512-U86xMaUOlBKUt6W92twIE03nsXesPY0TtpSOA7SRMFkKx+mw5HKY38V6fLuo+c6NRSyXaQIAo1X2IsnwVK5B9w==",
       "requires": {
         "@mapbox/sphericalmercator": "~1.1.0",
         "@mapbox/tiletype": "0.3.x",
@@ -67,7 +67,7 @@
         "@mapbox/sphericalmercator": {
           "version": "1.1.0",
           "resolved": "https://registry.npmjs.org/@mapbox/sphericalmercator/-/sphericalmercator-1.1.0.tgz",
-          "integrity": "sha1-87GvBCYgcWoSifxB4el/YQgjrv4="
+          "integrity": "sha512-pEsfZyG4OMThlfFQbCte4gegvHUjxXCjz0KZ4Xk8NdOYTQBLflj6U8PL05RPAiuRAMAQNUUKJuL6qYZ5Y4kAWA=="
         }
       }
     },
@@ -133,7 +133,7 @@
     "@mapbox/tilelive-vector": {
       "version": "4.2.0",
       "resolved": "https://registry.npmjs.org/@mapbox/tilelive-vector/-/tilelive-vector-4.2.0.tgz",
-      "integrity": "sha1-Zh+G1RDcfIkK+AznzbcJvk0F5ew=",
+      "integrity": "sha512-pWWMoK4emiCLqypAGFTIlAkM2sQtfRxjtnrzJkXTAY6BNo6GIKGMBT/yLTjqJNmQT11NQ10OkqfhW9XzyFkOzw==",
       "requires": {
         "@mapbox/sphericalmercator": "~1.0.5",
         "@mapbox/tilelive": "~5.12.0",
@@ -191,7 +191,7 @@
         "request": {
           "version": "2.83.0",
           "resolved": "https://registry.npmjs.org/request/-/request-2.83.0.tgz",
-          "integrity": "sha1-ygtl2gLtYpNYh4COb1EDgQNOM1Y=",
+          "integrity": "sha512-lR3gD69osqm6EYLk9wB/G1W/laGWjzH90t1vEa2xuxHD5KUrSzp9pUSfTm+YC5Nxt2T8nMPEvKlhbQayU7bgFw==",
           "requires": {
             "aws-sign2": "~0.7.0",
             "aws4": "^1.6.0",
@@ -230,7 +230,7 @@
         "tough-cookie": {
           "version": "2.3.4",
           "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-2.3.4.tgz",
-          "integrity": "sha1-7GDO44rGdQY//JelwYlwV47oNlU=",
+          "integrity": "sha512-TZ6TTfI5NtZnuyy/Kecv+CnoROnyXn2DN97LontgQpCwsX2XyLYCC0ENhYkehSOwAp8rTQKc/NUIF7BkQ5rKLA==",
           "requires": {
             "punycode": "^1.4.1"
           }
@@ -250,7 +250,7 @@
     "abbrev": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
-      "integrity": "sha1-+PLIh60Qv2f2NPAFtph/7TF5qsg="
+      "integrity": "sha512-nne9/IiQ/hzIhY6pdDnbBtz7DjPTKrY00P/zvPSm5pOFkl6xuGrGnXn/VtTNNfNtAfZ9/1RtehkszU9qcTii0Q=="
     },
     "acorn": {
       "version": "6.4.0",
@@ -310,12 +310,12 @@
     "aproba": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/aproba/-/aproba-1.2.0.tgz",
-      "integrity": "sha1-aALmJk79GMeQobDVF/DyYnvyyUo="
+      "integrity": "sha512-Y9J6ZjXtoYh8RnXVCMOU/ttDmk1aBjunq9vO0ta5x85WDQiQfUF9sIPBITdbiiIVcBo03Hi3jMxigBtsddlXRw=="
     },
     "are-we-there-yet": {
       "version": "1.1.5",
       "resolved": "https://registry.npmjs.org/are-we-there-yet/-/are-we-there-yet-1.1.5.tgz",
-      "integrity": "sha1-SzXClE8GKov82mZBB2A1D+nd/CE=",
+      "integrity": "sha512-5hYdAkZlcG8tOLujVDTgCT+uPX0VnpAH28gWsLfzpXYm7wP6mp5Q/gYyR7YQ0cKVJcXJnl3j2kpBan13PtQf6w==",
       "requires": {
         "delegates": "^1.0.0",
         "readable-stream": "^2.0.6"
@@ -324,7 +324,7 @@
     "argparse": {
       "version": "1.0.10",
       "resolved": "https://registry.npmjs.org/argparse/-/argparse-1.0.10.tgz",
-      "integrity": "sha1-vNZ5HqWuCXJeF+WtmIE0zUCz2RE=",
+      "integrity": "sha512-o5Roy6tNG4SL/FOkCAN6RzjiakZS25RLYFrcMttJqbdd8BWrnA+fGz57iN5Pb06pvBGvl5gQ0B48dJlslXvoTg==",
       "dev": true,
       "requires": {
         "sprintf-js": "~1.0.2"
@@ -333,7 +333,7 @@
     "asn1": {
       "version": "0.2.4",
       "resolved": "https://registry.npmjs.org/asn1/-/asn1-0.2.4.tgz",
-      "integrity": "sha1-jSR136tVO7M+d7VOWeiAu4ziMTY=",
+      "integrity": "sha512-jxwzQpLQjSmWXgwaCZE9Nz+glAG01yF1QnWgbhGwHI5A6FRIEY6IVqtHhIepHqI7/kyEyQEagBC5mBEFlIYvdg==",
       "requires": {
         "safer-buffer": "~2.1.0"
       }
@@ -346,7 +346,7 @@
     "astral-regex": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/astral-regex/-/astral-regex-1.0.0.tgz",
-      "integrity": "sha1-bIw/uCfdQ+45GPJ7gngqt2WKb9k=",
+      "integrity": "sha512-+Ryf6g3BKoRc7jfp7ad8tM4TtMiaWvbF/1/sQcZPkkS7ag3D5nMBCe2UfOTONtAkaG0tO0ij3C5Lwmf1EiyjHg==",
       "dev": true
     },
     "async": {
@@ -450,7 +450,7 @@
     "brace-expansion": {
       "version": "1.1.11",
       "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-1.1.11.tgz",
-      "integrity": "sha1-PH/L9SnYcibz0vUrlm/1Jx60Qd0=",
+      "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
       "requires": {
         "balanced-match": "^1.0.0",
         "concat-map": "0.0.1"
@@ -496,7 +496,7 @@
     "chardet": {
       "version": "0.7.0",
       "resolved": "https://registry.npmjs.org/chardet/-/chardet-0.7.0.tgz",
-      "integrity": "sha1-kAlISfCTfy7twkJdDSip5fDLrZ4=",
+      "integrity": "sha512-mT8iDcrh03qDGRRmoA2hmBJnxpllMR+0/0qlzjqZES6NdiWDcZkCNAk4rPFZ9Q85r27unkiNNg8ZOiwZXBHwcA==",
       "dev": true
     },
     "chownr": {
@@ -627,7 +627,7 @@
     "cross-spawn": {
       "version": "6.0.5",
       "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-6.0.5.tgz",
-      "integrity": "sha1-Sl7Hxk364iw6FBJNus3uhG2Ay8Q=",
+      "integrity": "sha512-eTVLrBSt7fjbDygz805pMnstIs2VTBNkRm0qxZd+M7A5XDdxVRWO5MxGBXZhjY4cqLYLdtrGqRf8mBPmzwSpWQ==",
       "dev": true,
       "requires": {
         "nice-try": "^1.0.4",
@@ -648,7 +648,7 @@
     "cryptiles": {
       "version": "3.1.4",
       "resolved": "https://registry.npmjs.org/cryptiles/-/cryptiles-3.1.4.tgz",
-      "integrity": "sha1-dppoyVYStW+q386/V6yGR5y+gyI=",
+      "integrity": "sha512-8I1sgZHfVwcSOY6mSGpVU3lw/GSIZvusg8dD2+OGehCJpOhQRLNcH0qb9upQnOH4XhgxxFJSg6E2kx95deb1Tw==",
       "requires": {
         "boom": "5.x.x"
       },
@@ -656,7 +656,7 @@
         "boom": {
           "version": "5.2.0",
           "resolved": "https://registry.npmjs.org/boom/-/boom-5.2.0.tgz",
-          "integrity": "sha1-XdnabuOl8wIHdDYpDLcX0/SlTgI=",
+          "integrity": "sha512-Z5BTk6ZRe4tXXQlkqftmsAUANpXmuwlsF5Oov8ThoMbQRzdGTA1ngYRW160GexgOgjsFOKJz0LYhoNi+2AMBUw==",
           "requires": {
             "hoek": "4.x.x"
           }
@@ -720,7 +720,7 @@
     "deep-extend": {
       "version": "0.6.0",
       "resolved": "https://registry.npmjs.org/deep-extend/-/deep-extend-0.6.0.tgz",
-      "integrity": "sha1-xPp8lUBKF6nD6Mp+FTcxK3NjMKw="
+      "integrity": "sha512-LOHxIOaPYdHlJRtCQfDIVZtfw/ufM8+rVj649RIHzcm/vGwQRXFt6OPqIFWsm2XEMrNIEtWR64sY1LEKD2vAOA=="
     },
     "deep-is": {
       "version": "0.1.3",
@@ -731,7 +731,7 @@
     "define-properties": {
       "version": "1.1.3",
       "resolved": "https://registry.npmjs.org/define-properties/-/define-properties-1.1.3.tgz",
-      "integrity": "sha1-z4jabL7ib+bbcJT2HYcMvYTO6fE=",
+      "integrity": "sha512-3MqfYKj2lLzdMSf8ZIZE/V+Zuy+BgD6f164e8K2w7dgnpKArBDerGYpM46IYYcjnkdPNMjPk9A6VFB8+3SKlXQ==",
       "dev": true,
       "requires": {
         "object-keys": "^1.0.12"
@@ -802,7 +802,7 @@
     "domelementtype": {
       "version": "1.3.1",
       "resolved": "https://registry.npmjs.org/domelementtype/-/domelementtype-1.3.1.tgz",
-      "integrity": "sha1-0EjESzew0Qp/Kj1f7j9DM9eQSB8=",
+      "integrity": "sha512-BSKB+TSpMpFI/HOxCNr1O8aMOTZ8hT3pM3GQ0w/mWRmkhEDSFJkkyzz4XQsBV44BChwGkrDfMyjVD0eA2aFV3w==",
       "dev": true
     },
     "domhandler": {
@@ -848,7 +848,7 @@
     "error-ex": {
       "version": "1.3.2",
       "resolved": "https://registry.npmjs.org/error-ex/-/error-ex-1.3.2.tgz",
-      "integrity": "sha1-tKxAZIEH/c3PriQvQovqihTU8b8=",
+      "integrity": "sha512-7dFHNmqeFSEt2ZBsCriorKnn3Z2pj+fd9kmI6QoWw4//DL+icEBfc0U7qJCisqrTsKTjw4fNFy2pW9OqStD84g==",
       "requires": {
         "is-arrayish": "^0.2.1"
       }
@@ -1051,7 +1051,7 @@
     "esquery": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/esquery/-/esquery-1.0.1.tgz",
-      "integrity": "sha1-QGxRZYsfWZGl+bYrHcJbAOPlxwg=",
+      "integrity": "sha512-SmiyZ5zIWH9VM+SRUReLS5Q8a7GxtRdxEBVZpm98rJM7Sb+A9DVCndXfkeFUd3byderg+EbDkfnevfCwynWaNA==",
       "dev": true,
       "requires": {
         "estraverse": "^4.0.0"
@@ -1060,7 +1060,7 @@
     "esrecurse": {
       "version": "4.2.1",
       "resolved": "https://registry.npmjs.org/esrecurse/-/esrecurse-4.2.1.tgz",
-      "integrity": "sha1-AHo7n9vCs7uH5IeeoZyS/b05Qs8=",
+      "integrity": "sha512-64RBB++fIOAXPw3P9cy89qfMlvZEXZkqqJkjqqXIvzP5ezRZjW+lPWjw35UX/3EhUPFYbg5ER4JYgDw4007/DQ==",
       "dev": true,
       "requires": {
         "estraverse": "^4.1.0"
@@ -1092,7 +1092,7 @@
     "extend": {
       "version": "3.0.2",
       "resolved": "https://registry.npmjs.org/extend/-/extend-3.0.2.tgz",
-      "integrity": "sha1-+LETa0Bx+9jrFAr/hYsQGewpFfo="
+      "integrity": "sha512-fjquC59cD7CyW6urNXK0FBufkZcoiGG80wTuPujX590cB5Ttln20E2UB4S/WARVqhXffZl2LNgS+gQdPIIim/g=="
     },
     "external-editor": {
       "version": "3.1.0",
@@ -1214,7 +1214,7 @@
     "for-each": {
       "version": "0.3.3",
       "resolved": "https://registry.npmjs.org/for-each/-/for-each-0.3.3.tgz",
-      "integrity": "sha1-abRH6IoKXTLD5whPPxcQA0shN24=",
+      "integrity": "sha512-jqYfLp7mo9vIyQf8ykW2v7A+2N4QjeCeI5+Dz9XraiO1ign81wjiH7Fb9vSOWvQfNtmSa4H2RoQTrrXivdUZmw==",
       "dev": true,
       "requires": {
         "is-callable": "^1.1.3"
@@ -1228,7 +1228,7 @@
     "form-data": {
       "version": "2.3.3",
       "resolved": "https://registry.npmjs.org/form-data/-/form-data-2.3.3.tgz",
-      "integrity": "sha1-3M5SwF9kTymManq5Nr1yTO/786Y=",
+      "integrity": "sha512-1lLKB2Mu3aGP1Q/2eCOx0fNbRMe7XdwktwOruhfqqd0rIJWwN4Dh+E3hrPSlDCXnSR7UtZ1N38rVXm+6+MEhJQ==",
       "requires": {
         "asynckit": "^0.4.0",
         "combined-stream": "^1.0.6",
@@ -1262,7 +1262,7 @@
     "function-bind": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/function-bind/-/function-bind-1.1.1.tgz",
-      "integrity": "sha1-pWiZ0+o8m6uHS7l3O3xe3pL0iV0=",
+      "integrity": "sha512-yIovAzMX49sF8Yl58fSCWJ5svSLuaibPxXQJFLmBObTuCr0Mf1KiPopGM9NiFjiYBCbfaa2Fh6breQ6ANVTI0A==",
       "dev": true
     },
     "functional-red-black-tree": {
@@ -1708,7 +1708,7 @@
     "get-caller-file": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/get-caller-file/-/get-caller-file-1.0.3.tgz",
-      "integrity": "sha1-+Xj6TJDR3+f/LWvtoqUV5xO9z0o="
+      "integrity": "sha512-3t6rVToeoZfYSGd8YoLFR2DJkiQrIiUrGcjvFX2mDw3bn6k2OtwHN0TNCLbBO+w8qTvimhDkv+LSscbJY1vE6w=="
     },
     "getpass": {
       "version": "0.1.7",
@@ -1770,7 +1770,7 @@
     "har-validator": {
       "version": "5.1.3",
       "resolved": "https://registry.npmjs.org/har-validator/-/har-validator-5.1.3.tgz",
-      "integrity": "sha1-HvievT5JllV2de7ZiTEQ3DUPoIA=",
+      "integrity": "sha512-sNvOCzEQNr/qrvJgc3UG/kD4QtlHycrzwS+6mfTrrSq97BvaYcPZZI1ZSqGSPR73Cxn4LKTD4PttRwfU7jWq5g==",
       "requires": {
         "ajv": "^6.5.5",
         "har-schema": "^2.0.0"
@@ -1779,7 +1779,7 @@
     "has": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/has/-/has-1.0.3.tgz",
-      "integrity": "sha1-ci18v8H2qoJB8W3YFOAR4fQeh5Y=",
+      "integrity": "sha512-f2dvO0VU6Oej7RkWJGrehjbzMAjFp5/VKPp5tTpWIV4JHHZK1/BxbFRtf/siA2SWTe09caDmVtYYzWEIbBS4zw==",
       "dev": true,
       "requires": {
         "function-bind": "^1.1.1"
@@ -1805,7 +1805,7 @@
     "hawk": {
       "version": "6.0.2",
       "resolved": "https://registry.npmjs.org/hawk/-/hawk-6.0.2.tgz",
-      "integrity": "sha1-r02RTrBl+bXOTZ0RwcshJu7MMDg=",
+      "integrity": "sha512-miowhl2+U7Qle4vdLqDdPt9m09K6yZhkLDTWGoUiUzrQCn+mHHSmfJgAyGaLRZbPmTqfFFjRV1QWCW0VWUJBbQ==",
       "requires": {
         "boom": "4.x.x",
         "cryptiles": "3.x.x",
@@ -1816,7 +1816,7 @@
     "hoek": {
       "version": "4.2.1",
       "resolved": "https://registry.npmjs.org/hoek/-/hoek-4.2.1.tgz",
-      "integrity": "sha1-ljRQKqEsRF3Vp8VzS1cruHOKrLs="
+      "integrity": "sha512-QLg82fGkfnJ/4iy1xZ81/9SIJiq1NGFUMGs6ParyjBZr6jW2Ufj/snDqTHixNlHdPNwN2RLVD0Pi3igeK9+JfA=="
     },
     "hosted-git-info": {
       "version": "2.8.5",
@@ -1875,7 +1875,7 @@
     "iconv-lite": {
       "version": "0.4.24",
       "resolved": "https://registry.npmjs.org/iconv-lite/-/iconv-lite-0.4.24.tgz",
-      "integrity": "sha1-ICK0sl+93CHS9SSXSkdKr+czkIs=",
+      "integrity": "sha512-v3MXnZAcvnywkTUEZomIActle7RXXeedOR31wwl7VlyoXO4Qi9arvSenNQWne1TcRwhCL1HwLI21bEqdpj8/rA==",
       "requires": {
         "safer-buffer": ">= 2.1.2 < 3"
       }
@@ -1932,7 +1932,7 @@
     "ini": {
       "version": "1.3.5",
       "resolved": "https://registry.npmjs.org/ini/-/ini-1.3.5.tgz",
-      "integrity": "sha1-7uJfVtscnsYIXgwid4CD9Zar+Sc="
+      "integrity": "sha512-RZY5huIKCMRWDUqZlEi72f/lmXKMvuszcMBduliQ3nnWbx9X/ZBQO7DijMEYS9EhHBb2qacRUMtC7svLwe0lcw=="
     },
     "inquirer": {
       "version": "6.5.2",
@@ -2230,7 +2230,7 @@
     "json-schema-traverse": {
       "version": "0.4.1",
       "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-0.4.1.tgz",
-      "integrity": "sha1-afaofZUTq4u4/mO9sJecRI5oRmA="
+      "integrity": "sha512-xbbCH5dCYU5T8LcEhhuh7HJ88HXuW3qsI3Y0zOZFKfZEHcpWiHU/Jxzk629Brsab/mMiHQti9wMP+845RPe3Vg=="
     },
     "json-stable-stringify-without-jsonify": {
       "version": "1.0.1",
@@ -2298,7 +2298,7 @@
     "log-driver": {
       "version": "1.2.7",
       "resolved": "https://registry.npmjs.org/log-driver/-/log-driver-1.2.7.tgz",
-      "integrity": "sha1-Y7lQIfBwL+36LJuwok53l9cYcdg=",
+      "integrity": "sha512-U7KCmLdqsGHBLeWqYlFA0V0Sl6P08EE1ZrmA9cxjUE0WVqT9qnyVDPz1kzpFEP0jdJuFnasWIfSd7fsaNXkpbg==",
       "dev": true
     },
     "mapbox-studio-default-fonts": {
@@ -2376,13 +2376,13 @@
     "mimic-fn": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/mimic-fn/-/mimic-fn-1.2.0.tgz",
-      "integrity": "sha1-ggyGo5M0ZA6ZUWkovQP8qIBX0CI=",
+      "integrity": "sha512-jf84uxzwiuiIVKiOLpfYk7N46TSy8ubTonmneY9vrpHNAnp0QBt2BxWV9dO3/j+BoVAb+a5G6YDPW3M5HOdMWQ==",
       "dev": true
     },
     "minimatch": {
       "version": "3.0.4",
       "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.0.4.tgz",
-      "integrity": "sha1-UWbihkV/AzBgZL5Ul+jbsMPTIIM=",
+      "integrity": "sha512-yJHVQEhyqPLUTgt9B83PXu6W3rx4MvvHvSUvToogpwoGDOUQ+yDrR0HRot+yOCdCO7u4hX3pWft6kWBBcqh0UA==",
       "requires": {
         "brace-expansion": "^1.1.7"
       }
@@ -2437,7 +2437,7 @@
     "nan": {
       "version": "2.10.0",
       "resolved": "https://registry.npmjs.org/nan/-/nan-2.10.0.tgz",
-      "integrity": "sha1-ltDNYQ69WNS03pzAxoKM2pnHVI8="
+      "integrity": "sha512-bAdJv7fBLhWC+/Bls0Oza+mvTaNQtP+1RyhhhvD95pgUJz6XM5IzgmxOkItJ9tkoCiplvAnXI1tNmmUD/eScyA=="
     },
     "natural-compare": {
       "version": "1.4.0",
@@ -2464,7 +2464,7 @@
     "nice-try": {
       "version": "1.0.5",
       "resolved": "https://registry.npmjs.org/nice-try/-/nice-try-1.0.5.tgz",
-      "integrity": "sha1-ozeKdpbOfSI+iPybdkvX7xCJ42Y=",
+      "integrity": "sha512-1nh45deeb5olNY7eX82BkPO7SSxR5SSYJiPTrTdFUVYwAl8CKMA5N9PjTYkHiRjisVcxcQ1HXdLhx2qxxJzLNQ==",
       "dev": true
     },
     "node-pre-gyp": {
@@ -2529,7 +2529,7 @@
     "npmlog": {
       "version": "4.1.2",
       "resolved": "https://registry.npmjs.org/npmlog/-/npmlog-4.1.2.tgz",
-      "integrity": "sha1-CKfyqL9zRgR3mp76StXMcXq7lUs=",
+      "integrity": "sha512-2uUqazuKlTaSI/dC8AzicUck7+IrEaOnN/e0jd3Xtt1KcGpwx30v50mL7oPyr/h9bL3E4aZccVwpwP+5W9Vjkg==",
       "requires": {
         "are-we-there-yet": "~1.1.2",
         "console-control-strings": "~1.1.0",
@@ -2550,7 +2550,7 @@
     "oauth-sign": {
       "version": "0.9.0",
       "resolved": "https://registry.npmjs.org/oauth-sign/-/oauth-sign-0.9.0.tgz",
-      "integrity": "sha1-R6ewFrqmi1+g7PPe4IqFxnmsZFU="
+      "integrity": "sha512-fexhUFFPTGV8ybAtSIGbV6gOkSv8UtRbDBnAyLQw4QPKkgNlsH2ByPGtMUqdWkos6YCRmAqViwgZrJc/mRDzZQ=="
     },
     "object-assign": {
       "version": "4.1.1",
@@ -2664,7 +2664,7 @@
     "osenv": {
       "version": "0.1.5",
       "resolved": "https://registry.npmjs.org/osenv/-/osenv-0.1.5.tgz",
-      "integrity": "sha1-hc36+uso6Gd/QW4odZK18/SepBA=",
+      "integrity": "sha512-0CWcCECdMVc2Rw3U5w9ZjqX6ga6ubk1xDVKxtBQPK7wis/0F2r9T6k4ydGYhecl7YUBxBVxhL5oisPsNxAPe2g==",
       "requires": {
         "os-homedir": "^1.0.0",
         "os-tmpdir": "^1.0.0"
@@ -2715,7 +2715,7 @@
     "path-parse": {
       "version": "1.0.6",
       "resolved": "https://registry.npmjs.org/path-parse/-/path-parse-1.0.6.tgz",
-      "integrity": "sha1-1i27VnlAXXLEc37FhgDp3c8G0kw="
+      "integrity": "sha512-GSmOT2EbHrINBf9SR7CDELwlJ8AENk3Qn7OikK4nFYAu3Ote2+JYNVvkpAEQm3/TLNEJFD/xZJjzyxg3KBWOzw=="
     },
     "path-type": {
       "version": "1.1.0",
@@ -2793,12 +2793,12 @@
     "punycode": {
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/punycode/-/punycode-2.1.1.tgz",
-      "integrity": "sha1-tYsBCsQMIsVldhbI0sLALHv0eew="
+      "integrity": "sha512-XRsRjdf+j5ml+y/6GKHPZbrF/8p2Yga0JPtdqTIY2Xe5ohJPD9saDJJLPvp9+NSBprVvevdXZybnj2cv8OEd0A=="
     },
     "qs": {
       "version": "6.5.2",
       "resolved": "https://registry.npmjs.org/qs/-/qs-6.5.2.tgz",
-      "integrity": "sha1-yzroBuh0BERYTvFUzo7pjUA/PjY="
+      "integrity": "sha512-N5ZAX4/LxJmF+7wN74pUD6qAh9/wnvdQcjq9TZjevvXzSUo7bfmw91saqMjzGS2xq91/odN2dW/WOl7qQHNDGA=="
     },
     "querystring": {
       "version": "0.2.0",
@@ -2813,7 +2813,7 @@
     "rc": {
       "version": "1.2.8",
       "resolved": "https://registry.npmjs.org/rc/-/rc-1.2.8.tgz",
-      "integrity": "sha1-zZJL9SAKB1uDwYjNa54hG3/A0+0=",
+      "integrity": "sha512-y3bGgqKj3QBdxLbLkomlohkvsA8gdAiUQlSBJnBhfn+BPxg4bc62d8TcBW15wavDfgexCgccckhcZvywyQYPOw==",
       "requires": {
         "deep-extend": "^0.6.0",
         "ini": "~1.3.0",
@@ -2874,13 +2874,13 @@
     "regexpp": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/regexpp/-/regexpp-2.0.1.tgz",
-      "integrity": "sha1-jRnTHPYySCtYkEn4KB+T28uk0H8=",
+      "integrity": "sha512-lv0M6+TkDVniA3aD1Eg0DVpfU/booSu7Eev3TDO/mZKHBfVjgCGTV4t4buppESEYDtkArYFOxTJWv6S5C+iaNw==",
       "dev": true
     },
     "request": {
       "version": "2.88.0",
       "resolved": "https://registry.npmjs.org/request/-/request-2.88.0.tgz",
-      "integrity": "sha1-nC/KT301tZLv5Xx/ClXoEFIST+8=",
+      "integrity": "sha512-NAqBSrijGLZdM0WZNsInLJpkJokL72XYjUpnB0iwsRgxh7dB6COrHnTBNwN0E+lHDAJzu7kLAkDeY08z2/A0hg==",
       "requires": {
         "aws-sign2": "~0.7.0",
         "aws4": "^1.8.0",
@@ -2907,7 +2907,7 @@
     "requestretry": {
       "version": "1.13.0",
       "resolved": "https://registry.npmjs.org/requestretry/-/requestretry-1.13.0.tgz",
-      "integrity": "sha1-IT7BAG7rdQ6LjOVBdig9FajVXZQ=",
+      "integrity": "sha512-Lmh9qMvnQXADGAQxsXHP4rbgO6pffCfuR8XUBdP9aitJcLQJxhp7YZK4xAVYXnPJ5E52mwrfiKQtKonPL8xsmg==",
       "requires": {
         "extend": "^3.0.0",
         "lodash": "^4.15.0",
@@ -3011,17 +3011,17 @@
     "safe-buffer": {
       "version": "5.1.2",
       "resolved": "https://registry.npmjs.org/safe-buffer/-/safe-buffer-5.1.2.tgz",
-      "integrity": "sha1-mR7GnSluAxN0fVm9/St0XDX4go0="
+      "integrity": "sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g=="
     },
     "safer-buffer": {
       "version": "2.1.2",
       "resolved": "https://registry.npmjs.org/safer-buffer/-/safer-buffer-2.1.2.tgz",
-      "integrity": "sha1-RPoWGwGHuVSd2Eu5GAL5vYOFzWo="
+      "integrity": "sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg=="
     },
     "sax": {
       "version": "1.2.4",
       "resolved": "https://registry.npmjs.org/sax/-/sax-1.2.4.tgz",
-      "integrity": "sha1-KBYjTiN4vdxOU1T6tcqold9xANk="
+      "integrity": "sha512-NqVDv9TpANUjFm0N8uM5GxL36UgKi9/atZw+x7YFnQ8ckwFGKrl4xX4yWtrey3UJm5nP1kUbnYgLopqWNSRhWw=="
     },
     "semver": {
       "version": "5.3.0",
@@ -3086,7 +3086,7 @@
     "sntp": {
       "version": "2.1.0",
       "resolved": "https://registry.npmjs.org/sntp/-/sntp-2.1.0.tgz",
-      "integrity": "sha1-LGzsFP7cIiJznK+bXD2F0cxaLMg=",
+      "integrity": "sha512-FL1b58BDrqS3A11lJ0zEdnJ3UOKqVxawAkF3k7F0CVN7VQ34aZrV+G8BZ1WC9ZL7NyrwsW0oviwsWDgRuVYtJg==",
       "requires": {
         "hoek": "4.x.x"
       }
@@ -3104,7 +3104,7 @@
     "spdx-correct": {
       "version": "3.1.0",
       "resolved": "https://registry.npmjs.org/spdx-correct/-/spdx-correct-3.1.0.tgz",
-      "integrity": "sha1-+4PlBERSaPFUsHTiGMh8ADzTHfQ=",
+      "integrity": "sha512-lr2EZCctC2BNR7j7WzJ2FpDznxky1sjfxvvYEyzxNyb6lZXHODmEoJeFu4JupYlkfha1KZpJyoqiJ7pgA1qq8Q==",
       "requires": {
         "spdx-expression-parse": "^3.0.0",
         "spdx-license-ids": "^3.0.0"
@@ -3113,12 +3113,12 @@
     "spdx-exceptions": {
       "version": "2.2.0",
       "resolved": "https://registry.npmjs.org/spdx-exceptions/-/spdx-exceptions-2.2.0.tgz",
-      "integrity": "sha1-LqRQrudPKom/uUUZwH/Nb0EyKXc="
+      "integrity": "sha512-2XQACfElKi9SlVb1CYadKDXvoajPgBVPn/gOQLrTvHdElaVhr7ZEbqJaRnJLVNeaI4cMEAgVCeBMKF6MWRDCRA=="
     },
     "spdx-expression-parse": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/spdx-expression-parse/-/spdx-expression-parse-3.0.0.tgz",
-      "integrity": "sha1-meEZt6XaAOBUkcn6M4t5BII7QdA=",
+      "integrity": "sha512-Yg6D3XpRD4kkOmTpdgbUiEJFKghJH03fiC1OPll5h/0sO6neh2jqRDVHOQ4o/LMea0tgCkbMgea5ip/e+MkWyg==",
       "requires": {
         "spdx-exceptions": "^2.1.0",
         "spdx-license-ids": "^3.0.0"
@@ -3145,7 +3145,7 @@
     "split": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/split/-/split-1.0.1.tgz",
-      "integrity": "sha1-YFvZvjA6pZ+zX5Ip++oN3snqB9k=",
+      "integrity": "sha512-mTyOoPbrivtXnwnIxZRFYRrPNtEFKlpB2fvjSnCQUiAA6qAZzqwna5envK4uk6OIeP17CsdF3rSBGYVBsU0Tkg==",
       "requires": {
         "through": "2"
       }
@@ -3271,7 +3271,7 @@
     "stringstream": {
       "version": "0.0.6",
       "resolved": "https://registry.npmjs.org/stringstream/-/stringstream-0.0.6.tgz",
-      "integrity": "sha1-eIAiWw1K0Q4wkn0Weh1vL9OzOnI="
+      "integrity": "sha512-87GEBAkegbBcweToUrdzf3eLhWNg06FJTebl4BVJz/JgWy8CvEr9dRtX5qWphiynMSQlxxi+QqN0z5T32SLlhA=="
     },
     "strip-ansi": {
       "version": "3.0.1",
@@ -3439,7 +3439,7 @@
     "tmp": {
       "version": "0.0.33",
       "resolved": "https://registry.npmjs.org/tmp/-/tmp-0.0.33.tgz",
-      "integrity": "sha1-bTQzWIl2jSGyvNoKonfO07G/rfk=",
+      "integrity": "sha512-jRCJlojKnZ3addtTOjdIqoRuPEKBvNXcGYqzO6zWZX8KfKEpnGY5jfggJQ3EjKuu8D4bJRr0y+cYJFmYbImXGw==",
       "dev": true,
       "requires": {
         "os-tmpdir": "~1.0.2"
@@ -3448,7 +3448,7 @@
     "tough-cookie": {
       "version": "2.4.3",
       "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-2.4.3.tgz",
-      "integrity": "sha1-U/Nto/R3g7CSWvoG/587FlKA94E=",
+      "integrity": "sha512-Q5srk/4vDM54WJsJio3XNn6K2sCG+CQ8G5Wz6bZhRZoAe/+TxjWB/GlFAnYEbkYVlON9FMk/fE3h2RLpPXo4lQ==",
       "requires": {
         "psl": "^1.1.24",
         "punycode": "^1.4.1"
@@ -3512,12 +3512,12 @@
     "underscore": {
       "version": "1.9.1",
       "resolved": "https://registry.npmjs.org/underscore/-/underscore-1.9.1.tgz",
-      "integrity": "sha1-BtzjSg5op7q8KbNluOdLiSUgOWE="
+      "integrity": "sha512-5/4etnCkd9c8gwgowi5/om/mYO5ajCaOgdzj/oW+0eQV9WxKBDZw5+ycmKmeaTXjInS/W0BzpGLo2xR2aBwZdg=="
     },
     "uri-js": {
       "version": "4.2.2",
       "resolved": "https://registry.npmjs.org/uri-js/-/uri-js-4.2.2.tgz",
-      "integrity": "sha1-lMVA4f93KVbiKZUHwBCupsiDjrA=",
+      "integrity": "sha512-KY9Frmirql91X2Qgjry0Wd4Y+YTdrdZheS8TFwvkbLWf/G5KNJDCh6pKL5OZctEW4+0Baa5idK2ZQuELRwPznQ==",
       "requires": {
         "punycode": "^2.1.0"
       }
@@ -3551,7 +3551,7 @@
     "validate-npm-package-license": {
       "version": "3.0.4",
       "resolved": "https://registry.npmjs.org/validate-npm-package-license/-/validate-npm-package-license-3.0.4.tgz",
-      "integrity": "sha1-/JH2uce6FchX9MssXe/uw51PQQo=",
+      "integrity": "sha512-DpKm2Ui/xN7/HQKCtpZxoRWBhZ9Z0kqtygG8XCgNQ8ZlDnxuQmWhj566j8fN4Cu3/JmbhsDo7fcAJq4s9h27Ew==",
       "requires": {
         "spdx-correct": "^3.0.0",
         "spdx-expression-parse": "^3.0.0"
@@ -3580,7 +3580,7 @@
     "which": {
       "version": "1.3.1",
       "resolved": "https://registry.npmjs.org/which/-/which-1.3.1.tgz",
-      "integrity": "sha1-pFBD1U9YBTFtqNYvn1CRjT2nCwo=",
+      "integrity": "sha512-HxJdYWq1MTIQbJ3nw0cqssHoTNU267KlrDuGZ1WYlxDStUtKUhOaJmh112/TZmHxxUfuJqPXSOm7tDyas0OSIQ==",
       "dev": true,
       "requires": {
         "isexe": "^2.0.0"
@@ -3594,7 +3594,7 @@
     "wide-align": {
       "version": "1.1.3",
       "resolved": "https://registry.npmjs.org/wide-align/-/wide-align-1.1.3.tgz",
-      "integrity": "sha1-rgdOa9wMFKQx6ATmJFScYzsABFc=",
+      "integrity": "sha512-QGkOQc8XL6Bt5PwnsExKBPuMKBxnGxWWW3fU55Xt4feHozMUhdUMaBCk290qpm/wG5u/RSKzwdAC4i51YigihA==",
       "requires": {
         "string-width": "^1.0.2 || 2"
       }
@@ -3637,7 +3637,7 @@
     "xml2js": {
       "version": "0.4.19",
       "resolved": "https://registry.npmjs.org/xml2js/-/xml2js-0.4.19.tgz",
-      "integrity": "sha1-aGwg8hMgnpSr8NG88e+qKRx4J6c=",
+      "integrity": "sha512-esZnJZJOiJR9wWKMyuvSE1y6Dq5LCuJanqhxslH2bxM6duahNZ+HMpCLhBQGZkbX6xRf8x1Y2eJlgt2q3qo49Q==",
       "requires": {
         "sax": ">=0.6.0",
         "xmlbuilder": "~9.0.1"
diff --git a/package.json b/package.json
index 8bc3c7a..b2fbce9 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@mapbox/mapbox-upload-validate",
-  "version": "4.7.0",
+  "version": "4.8.0",
   "description": "Validate that a file can be uploaded to Mapbox",
   "main": "index.js",
   "scripts": {
diff --git a/test/expected/index.js b/test/expected/index.js
index 81c4455..9cb64df 100644
--- a/test/expected/index.js
+++ b/test/expected/index.js
@@ -81,7 +81,8 @@ module.exports = {
     'nulltile': 'Tile is invalid',
     'prepare': 'Source cannot contain prepare key',
     'filetoobig': 'File is larger than 1.02 kB. Too big to process.',
-    'zoomleveltoobig': 'Maxzoom exceeded for mbtiles file. There is a max zoom limit of 0 but tiles up to zoom level 1 were found. If you need support for 1cm tilesets please reach out to support.'
+    'zoomleveltoobig': 'Maxzoom exceeded for mbtiles file. There is a max zoom limit of 0 but tiles up to zoom level 1 were found. If you need support for 1cm tilesets please reach out to support.',
+    'duplicate_layers': 'Vector source "vector_layers" contains duplicate ID: apples'
   },
   unsupportedErrors: 'Unknown filetype'
 };
diff --git a/test/fixtures/index.js b/test/fixtures/index.js
index db45fc0..faaa151 100644
--- a/test/fixtures/index.js
+++ b/test/fixtures/index.js
@@ -69,7 +69,8 @@ module.exports = {
       'empty': path.join(__dirname, 'invalid.mbtiles-empty.mbtiles'),
       'limits': path.join(__dirname, 'invalid.mbtiles-limits.mbtiles'),
       'nulltile': path.join(__dirname, 'invalid.mbtiles-null-tile.mbtiles'),
-      'prepare': path.join(__dirname, 'invalid.mbtiles-prepare.mbtiles')
+      'prepare': path.join(__dirname, 'invalid.mbtiles-prepare.mbtiles'),
+      'duplicate_layers': path.join(__dirname, 'invalid.mbtiles-duplicate-layers.mbtiles')
     }
   }
 };
diff --git a/test/fixtures/invalid.mbtiles-duplicate-layers.mbtiles b/test/fixtures/invalid.mbtiles-duplicate-layers.mbtiles
new file mode 100644
index 0000000..6b8c76a
Binary files /dev/null and b/test/fixtures/invalid.mbtiles-duplicate-layers.mbtiles differ
diff --git a/test/validators.mbtiles.test.js b/test/validators.mbtiles.test.js
index a92d672..24bc7f4 100644
--- a/test/validators.mbtiles.test.js
+++ b/test/validators.mbtiles.test.js
@@ -177,3 +177,12 @@ test('lib.validators.mbtiles: metadata fillzoom below tiles', function(t) {
     t.end();
   });
 });
+
+test('lib.validators.mbtiles: duplicate layers not allowed', function(t) {
+  validate(fixtures.invalid.mbtiles.duplicate_layers, function(err) {
+    t.ok(err, 'expected error');
+    t.equal(err.code, 'EINVALID', 'expected error code');
+    t.equal(err.message, expected.mbtilesErrors.duplicate_layers, 'expected error message');
+    t.end();
+  });
+});