diff --git a/lib/adapter.js b/lib/adapter.js
index 05ac584..5881965 100644
--- a/lib/adapter.js
+++ b/lib/adapter.js
@@ -19,9 +19,7 @@ module.exports = function createMySQLAdapter(client, settings) {
         disconnect: cb => client.end(cb),
         closeConnection: () => {
             return new Promise(resolve => {
-                client.end(function() {
-                    resolve();
-                });
+                client.end(() => resolve());
             });
         },
         define: spec => informationSchema.registerModel(spec.model.modelName, spec),
diff --git a/lib/enum-factory.js b/lib/enum-factory.js
index e9609a7..063e68f 100644
--- a/lib/enum-factory.js
+++ b/lib/enum-factory.js
@@ -1,7 +1,7 @@
 const EnumFactory = function() {
     if (arguments.length > 0) {
         const Enum = function Enum(arg) {
-            if (typeof arg === 'number' && arg % 1 == 0) {
+            if (typeof arg === 'number' && arg % 1 === 0) {
                 return Enum._values[arg];
             } else if (Enum[arg]) {
                 return Enum[arg];
@@ -9,31 +9,29 @@ const EnumFactory = function() {
                 return arg;
             } else if (arg === null) {
                 return null;
-            } else {
-                return '';
             }
+            return '';
         };
         const dxList = [];
-        dxList.push(''); // Want empty value to be at index 0 to match MySQL Enum values and MySQL non-strict behavior.
-        for (let arg in arguments) {
-            arg = String(arguments[arg]);
+        // Want empty value to be at index 0 to match MySQL Enum values and MySQL non-strict behavior.
+        dxList.push('');
+        [].slice.call(arguments).forEach(arg => {
             Object.defineProperty(Enum, arg.toUpperCase(), { configurable: false, enumerable: true, value: arg, writable: false });
             dxList.push(arg);
-        }
+        });
         Object.defineProperty(Enum, '_values', { configurable: false, enumerable: false, value: dxList, writable: false });
         Object.defineProperty(Enum, '_members', { configurable: false, enumerable: false, value: dxList.slice(1), writable: false });
         Object.defineProperty(Enum, '_string', { configurable: false, enumerable: false, value: stringified(Enum), writable: false });
         Object.freeze(Enum);
         return Enum;
-    } else {
-        throw 'No arguments - could not create Enum.';
     }
+    throw 'No arguments - could not create Enum.';
 };
 
 function stringified(anEnum) {
     const s = [];
     for (const i in anEnum._values) {
-        if (anEnum._values[i] != '') {
+        if (anEnum._values[i] !== '') {
             s.push('\'' + anEnum._values[i] + '\'');
         }
     }
diff --git a/lib/information-schema.js b/lib/information-schema.js
index 9253af5..bd31dda 100644
--- a/lib/information-schema.js
+++ b/lib/information-schema.js
@@ -73,18 +73,33 @@ module.exports = function() {
             throw new Error(`Unexpected ("object") type for ${ model }.${ key }`);
         }
 
-        if (!prop || 'undefined' === typeof val) return val;
-        if (prop.type.name === 'Number') return val;
-        if (val === null) return 'NULL';
+        if (!prop || 'undefined' === typeof val) {
+            return val;
+        }
+
+        if (prop.type.name === 'Number') {
+            return val;
+        }
+
+        if (val === null) {
+            return 'NULL';
+        }
+
         if (prop.type.name === 'Date') {
-            if (!val) return 'NULL';
+            if (!val) {
+                return 'NULL';
+            }
+
             if (!val.toUTCString) {
                 val = new Date(val);
             }
+
             return val;
         }
 
-        if (prop.type.name === 'Boolean') return val ? 1 : 0;
+        if (prop.type.name === 'Boolean') {
+            return val ? 1 : 0;
+        }
 
         return val.toString();
     }
@@ -132,13 +147,15 @@ module.exports = function() {
             sql = [ '`id` INT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY' ];
         }
 
-        Object.keys(models[model].properties).forEach(function(prop) {
-            if (prop === 'id') return;
+        Object.keys(models[model].properties).forEach(prop => {
+            if (prop === 'id') {
+                return;
+            }
             sql.push('`' + prop + '` ' + propertySettingsSQL(model, prop));
         });
 
         // Declared in model index property indexes.
-        Object.keys(models[model].properties).forEach(function(prop) {
+        Object.keys(models[model].properties).forEach(prop => {
             const p = models[model].properties[prop];
             const i = p.index;
             if (i && !(p.type instanceof Array)) {
@@ -149,7 +166,7 @@ module.exports = function() {
         // Settings might not have an indexes property.
         const dxs = models[model].settings.indexes;
         if (dxs) {
-            Object.keys(dxs).forEach(function(prop) {
+            Object.keys(dxs).forEach(prop => {
                 const ix = dxs[prop];
                 sql.push(formatIndexDefinition(prop, ix.kind, ix.type, ix.keys, ix.columns));
             });
@@ -194,7 +211,8 @@ module.exports = function() {
                 dt = numericOptionsByType(p, dt);
                 break;
             case 'Date':
-                dt = columnType(p, 'DATETIME'); // Currently doesn't need options.
+                // Currently doesn't need options.
+                dt = columnType(p, 'DATETIME');
                 break;
             case 'Boolean':
                 dt = 'TINYINT(1)';
@@ -204,7 +222,8 @@ module.exports = function() {
                 break;
             case 'Enum':
                 dt = 'ENUM(' + p.type._string + ')';
-                dt = stringOptions(p, dt); // Enum columns can have charset/collation.
+                // Enum columns can have charset/collation.
+                dt = stringOptions(p, dt);
                 break;
         }
         return dt;
diff --git a/lib/lookup-by-query.js b/lib/lookup-by-query.js
index 35308e2..6471220 100644
--- a/lib/lookup-by-query.js
+++ b/lib/lookup-by-query.js
@@ -71,8 +71,10 @@ module.exports = function(informationSchema, db) {
             });
 
         function buildOrderBy(order) {
-            if (typeof order === 'string') order = [ order ];
-            return 'ORDER BY ' + order.map(function(o) {
+            if (typeof order === 'string') {
+                order = [ order ];
+            }
+            return 'ORDER BY ' + order.map(o => {
                 const t = o.split(/\s+/);
                 if (t.length === 1) {
                     return '`' + o + '`';
@@ -82,10 +84,15 @@ module.exports = function(informationSchema, db) {
         }
 
         function buildGroupBy(group) {
-            if (typeof group === 'string') group = [ group ];
-            return 'GROUP BY ' + group.map(function(o) {
+            if (typeof group === 'string') {
+                group = [ group ];
+            }
+
+            return 'GROUP BY ' + group.map(o => {
                 const t = o.split(/\s+/);
-                if (t.length === 1) return '`' + o + '`';
+                if (t.length === 1) {
+                    return '`' + o + '`';
+                }
                 return '`' + t[0] + '` ' + t[1];
             }).join(', ');
         }
diff --git a/lib/mysql.js b/lib/mysql.js
index a9b7759..db8953d 100644
--- a/lib/mysql.js
+++ b/lib/mysql.js
@@ -24,7 +24,7 @@ exports.initialize = function initializeSchema(schema, callback) {
 
 function initializeConnection(connection, schema, callback) {
     // Attach listeners first
-    connection.on('error', function(err) {
+    connection.on('error', err => {
         schema.log('connection error', err);
         schema.connected = false;
     });
@@ -32,7 +32,7 @@ function initializeConnection(connection, schema, callback) {
     if (schema.settings.pool) {
         callback();
     } else {
-        connection.connect(function(err) {
+        connection.connect(err => {
             if (err) {
                 console.log('connection.connect err', err);
                 console.log('will reconnect in 60 secs');
diff --git a/lib/schema-operations.js b/lib/schema-operations.js
index 63e399d..dc66003 100644
--- a/lib/schema-operations.js
+++ b/lib/schema-operations.js
@@ -199,8 +199,10 @@ module.exports = function(informationSchema, db, settings) {
             .map(f => `DROP COLUMN ${ escapeKey(f.Field) }`));
 
         // remove indexes
-        aiNames.forEach(function(indexName) {
-            if (indexName === 'id' || indexName === 'PRIMARY') return;
+        aiNames.forEach(indexName => {
+            if (indexName === 'id' || indexName === 'PRIMARY') {
+                return;
+            }
             if (indexNames.indexOf(indexName) === -1 && !m.properties[indexName] || m.properties[indexName] && (!m.properties[indexName].index || m.properties[indexName].type instanceof Array || m.properties[indexName].type.name === 'JSON')) {
                 sql.push('DROP INDEX `' + indexName + '`');
             } else {
@@ -215,8 +217,10 @@ module.exports = function(informationSchema, db, settings) {
                     if (m.settings.indexes[indexName].keys) {
                         m.settings.indexes[indexName].columns = m.settings.indexes[indexName].keys.join(',');
                     }
-                    m.settings.indexes[indexName].columns.split(/,\s*/).forEach(function(columnName, i) {
-                        if (ai[indexName].columns[i] !== columnName) orderMatched = false;
+                    m.settings.indexes[indexName].columns.split(/,\s*/).forEach((columnName, i) => {
+                        if (ai[indexName].columns[i] !== columnName) {
+                            orderMatched = false;
+                        }
                     });
                 }
                 if (!orderMatched) {
@@ -263,17 +267,32 @@ module.exports = function(informationSchema, db, settings) {
         }
 
         function changed(newSettings, oldSettings) {
-            if (oldSettings.Null === 'YES') { // Used to allow null and does not now.
-                if (newSettings.allowNull === false) return true;
-                if (newSettings.null === false) return true;
+            // Used to allow null and does not now.
+            if (oldSettings.Null === 'YES') {
+                if (newSettings.allowNull === false) {
+                    return true;
+                }
+                if (newSettings.null === false) {
+                    return true;
+                }
+            }
+            // Did not allow null and now does.
+            if (oldSettings.Null === 'NO') {
+                if (newSettings.allowNull === true) {
+                    return true;
+                }
+                if (newSettings.null === true) {
+                    return true;
+                }
+                if (typeof newSettings.null === 'undefined' && typeof newSettings.allowNull === 'undefined') {
+                    return true;
+                }
             }
-            if (oldSettings.Null === 'NO') { // Did not allow null and now does.
-                if (newSettings.allowNull === true) return true;
-                if (newSettings.null === true) return true;
-                if (typeof newSettings.null === 'undefined' && typeof newSettings.allowNull === 'undefined') return true;
+
+            if (oldSettings.Type.toUpperCase() !== dataType(newSettings).toUpperCase()) {
+                return true;
             }
 
-            if (oldSettings.Type.toUpperCase() !== dataType(newSettings).toUpperCase()) return true;
             return false;
         }
     }