diff --git a/sanitizer/_categories.js b/sanitizer/_categories.js
index f3620fc20..291848d3a 100644
--- a/sanitizer/_categories.js
+++ b/sanitizer/_categories.js
@@ -2,7 +2,8 @@ const _ = require('lodash');
 const categoryTaxonomy = require('pelias-categories');
 
 const WARNINGS = {
-  empty: 'Categories parameter left blank, showing results from all categories.'
+  empty: 'Categories parameter left blank, showing results from all categories.',
+  notEmpty: 'Categories filtering not supported on this endpoint, showing results from all categories.'
 };
 
 // validate inputs, convert types and apply defaults
@@ -38,11 +39,25 @@ function _sanitize (raw, clean, categories) {
   return messages;
 }
 
+function _alwaysBlank (raw, clean, categories) {
+  // error & warning messages
+  const messages = { errors: [], warnings: [] };
+
+  if (raw.hasOwnProperty('categories')) {
+    clean.categories = [];
+    if (_.isString(raw.categories) && !_.isEmpty(raw.categories)) {
+      messages.warnings.push(WARNINGS.notEmpty);
+    }
+  }
+
+  return messages;
+}
+
 function _expected () {
   return [{ name: 'categories' }];
 }
 // export function
-module.exports = () => ({
-  sanitize: _sanitize,
+module.exports = (alwaysBlank) => ({
+  sanitize: alwaysBlank ? _alwaysBlank : _sanitize,
   expected: _expected
 });
diff --git a/sanitizer/place.js b/sanitizer/place.js
index 9b7c7fdb7..4395cc887 100644
--- a/sanitizer/place.js
+++ b/sanitizer/place.js
@@ -4,6 +4,7 @@ var sanitizeAll = require('../sanitizer/sanitizeAll'),
       debug: require('../sanitizer/_debug')(),
       ids: require('../sanitizer/_ids')(),
       private: require('../sanitizer/_flag_bool')('private', false),
+      categories: require('../sanitizer/_categories')(true),
       request_language: require('../sanitizer/_request_language')()
     };
 
diff --git a/test/unit/sanitizer/_categories.js b/test/unit/sanitizer/_categories.js
index 655a7b0e0..8593dd8ee 100644
--- a/test/unit/sanitizer/_categories.js
+++ b/test/unit/sanitizer/_categories.js
@@ -183,6 +183,91 @@ module.exports.tests.invalid_categories = function(test, common) {
   });
 };
 
+module.exports.tests.always_blank = function(test, common) {
+  const alwaysBlankSanitizer = require( '../../../sanitizer/_categories')(true);
+  test('garbage category', function(t) {
+    const req = {
+      query: {
+        categories: 'barf'
+      },
+      clean: { }
+    };
+    const expected_messages = { errors: [], warnings: [
+      'Categories filtering not supported on this endpoint, showing results from all categories.'
+    ] };
+
+    const messages = alwaysBlankSanitizer.sanitize(req.query, req.clean);
+
+    t.deepEqual(messages, expected_messages, 'error with message returned');
+    t.deepEqual(req.clean.categories, [], 'should return empty array');
+    t.end();
+  });
+
+  test('all garbage categories', function(t) {
+    const req = {
+      query: {
+        categories: 'food'
+      },
+      clean: { }
+    };
+    const expected_messages = { errors: [], warnings: [
+      'Categories filtering not supported on this endpoint, showing results from all categories.'
+    ] };
+
+    const messages = alwaysBlankSanitizer.sanitize(req.query, req.clean);
+
+    t.deepEqual(messages, expected_messages, 'error with message returned');
+    t.deepEqual(req.clean.categories, [], 'should return empty array');
+    t.end();
+  });
+
+  test('defined categories', function(t) {
+    const req = {
+      query: {
+        categories: undefined
+      },
+      clean: { }
+    };
+    const expected_messages = { errors: [], warnings: [] };
+
+    const messages = alwaysBlankSanitizer.sanitize(req.query, req.clean);
+
+    t.deepEqual(messages, expected_messages, 'error with message returned');
+    t.deepEqual(req.clean.categories, [], 'should return empty array');
+    t.end();
+  });
+
+  test('empty categories', function(t) {
+    const req = {
+      query: {
+        categories: ''
+      },
+      clean: { }
+    };
+    const expected_messages = { errors: [], warnings: [] };
+
+    const messages = alwaysBlankSanitizer.sanitize(req.query, req.clean);
+
+    t.deepEqual(messages, expected_messages, 'error with message returned');
+    t.deepEqual(req.clean.categories, [], 'should return empty array');
+    t.end();
+  });
+
+  test('not defined categories', function(t) {
+    const req = {
+      query: { },
+      clean: { }
+    };
+    const expected_messages = { errors: [], warnings: [] };
+
+    const messages = alwaysBlankSanitizer.sanitize(req.query, req.clean);
+
+    t.deepEqual(messages, expected_messages, 'error with message returned');
+    t.deepEqual(req.clean.categories, undefined, 'categories should be undefined');
+    t.end();
+  });
+};
+
 module.exports.all = function (tape, common) {
   function test(name, testFunction) {
     return tape('SANITIZE _categories ' + name, testFunction);