diff --git a/Document.js b/Document.js
index 17d0bf1..40b4a1b 100644
--- a/Document.js
+++ b/Document.js
@@ -246,7 +246,7 @@ Document.prototype.hasAddress = model.hasChild( 'address_parts' );
 // population
 Document.prototype.setPopulation = model.set( 'population', null, null )
                                         .validate( valid.type('number') )
-                                        .validate( valid.positive() );
+                                        .validate( valid.nonnegative() );
 
 Document.prototype.getPopulation = model.get( 'population' );
 
@@ -254,7 +254,7 @@ Document.prototype.getPopulation = model.get( 'population' );
 Document.prototype.setPopularity = model.set( 'popularity', null, null )
                                         .transform( transform.roundify() )
                                         .validate( valid.type('number') )
-                                        .validate( valid.positive() );
+                                        .validate( valid.nonnegative() );
 
 Document.prototype.getPopularity = model.get( 'popularity' );
 
diff --git a/test/run.js b/test/run.js
index f27312f..5a135ee 100644
--- a/test/run.js
+++ b/test/run.js
@@ -26,6 +26,7 @@ var tests = [
   require('./DocumentMapperStream.js'),
   require('./util/transform.js'),
   require('./util/model.js'),
+  require('./util/valid.js'),
   require('./serialize/test.js'),
 ];
 
diff --git a/test/util/valid.js b/test/util/valid.js
new file mode 100644
index 0000000..3ca2d51
--- /dev/null
+++ b/test/util/valid.js
@@ -0,0 +1,32 @@
+const valid = require('../../util/valid');
+
+module.exports.tests = {};
+
+module.exports.tests.nonnegative = (test) => {
+  test('nonnegative should throw error if value is less than 0', (t) => {
+    t.throws(valid.nonnegative().bind(null, -1), /invalid document type, expecting: 0 or a positive number, got: -1/);
+    t.end();
+  });
+
+  test('nonnegative should not throw error if value is 0', (t) => {
+    t.doesNotThrow(valid.nonnegative().bind(null, 0), '0 should be allowed');
+    t.end();
+  });
+
+  test('nonnegative should not throw error if value is greater than 0', (t) => {
+    t.doesNotThrow(valid.nonnegative().bind(null, 1), '1 should be allowed');
+    t.end();
+  });
+
+};
+
+module.exports.all = (tape, common) => {
+
+  function test(name, testFunction) {
+    return tape(`valid: ${name}`, testFunction);
+  }
+
+  for( var testCase in module.exports.tests ){
+    module.exports.tests[testCase](test, common);
+  }
+};
diff --git a/util/valid.js b/util/valid.js
index bad48ef..d4832f5 100644
--- a/util/valid.js
+++ b/util/valid.js
@@ -33,7 +33,7 @@ module.exports.truthy = function(){
   };
 };
 
-module.exports.positive = function(){
+module.exports.nonnegative = function(){
   return function( val ){
     if( val < 0 ){
       throw new PeliasModelError( 'invalid document type, expecting: 0 or a positive number, got: ' + val );