diff --git a/packages/strapi-hook-bookshelf/lib/index.js b/packages/strapi-hook-bookshelf/lib/index.js
index ff0d8fc8d0..5d4ddbc11c 100755
--- a/packages/strapi-hook-bookshelf/lib/index.js
+++ b/packages/strapi-hook-bookshelf/lib/index.js
@@ -456,15 +456,15 @@ module.exports = function(strapi) {
                       }, start);
                     };
 
-                    const generateIndexes = async (table, attrs) => {
+                    const generateIndexes = async (table) => {
                       try {
                         const connection = strapi.config.connections[definition.connection];
                         let columns = Object.keys(attributes).filter(attribute => ['string', 'text'].includes(attributes[attribute].type));
 
                         switch (connection.settings.client) {
-                          case 'pg':
+                          case 'pg': {
                             // Enable extension to allow GIN indexes.
-                            await ORM.knex.raw(`CREATE EXTENSION IF NOT EXISTS pg_trgm`);
+                            await ORM.knex.raw('CREATE EXTENSION IF NOT EXISTS pg_trgm');
 
                             // Create GIN indexes for every column.
                             const indexes = columns
@@ -479,6 +479,8 @@ module.exports = function(strapi) {
 
                             await Promise.all(indexes);
                             break;
+                          }
+
                           default:
                             columns = columns
                               .map(attribute => `\`${attribute}\``)
@@ -685,9 +687,8 @@ module.exports = function(strapi) {
                         ),
                         table => {
                           return _.snakeCase(
-                            pluralize.plural(table.collection) +
-                              ' ' +
-                              pluralize.plural(table.via)
+                            // eslint-disable-next-line prefer-template
+                            pluralize.plural(table.collection) + ' ' + pluralize.plural(table.via)
                           );
                         }
                       ).join('__');
@@ -704,7 +705,7 @@ module.exports = function(strapi) {
                   resolve();
                 }));
               } catch (err) {
-                strapi.log.error('Impossible to register the `' + model + '` model.');
+                strapi.log.error(`Impossible to register the '${model}' model.`);
                 strapi.log.error(err);
                 strapi.stop();
               }
@@ -822,9 +823,8 @@ module.exports = function(strapi) {
                       ),
                       table => {
                         return _.snakeCase(
-                          pluralize.plural(table.collection) +
-                            ' ' +
-                            pluralize.plural(table.via)
+                          // eslint-disable-next-line prefer-template
+                          pluralize.plural(table.collection) + ' ' + pluralize.plural(table.via)
                         );
                       }
                     ).join('__');
@@ -848,10 +848,7 @@ module.exports = function(strapi) {
 
                   // Sometimes the many-to-many relationships
                   // is on the same keys on the same models (ex: `friends` key in model `User`)
-                  if (
-                    details.attribute + '_' + details.column ===
-                    relationship.attribute + '_' + relationship.column
-                  ) {
+                  if (`${details.attribute}_${details.column}` === `${relationship.attribute}_${relationship.column}`) {
                     relationship.attribute = pluralize.singular(details.via);
                   }
 
@@ -866,16 +863,16 @@ module.exports = function(strapi) {
                       return this.belongsToMany(
                         GLOBALS[globalId],
                         collectionName,
-                        relationship.attribute + '_' + relationship.column,
-                        details.attribute + '_' + details.column
+                        `${relationship.attribute}_${relationship.column}`,
+                        `${details.attribute}_${details.column}`
                       ).withPivot(details.withPivot);
                     }
 
                     return this.belongsToMany(
                       GLOBALS[globalId],
                       collectionName,
-                      relationship.attribute + '_' + relationship.column,
-                      details.attribute + '_' + details.column
+                      `${relationship.attribute}_${relationship.column}`,
+                      `${details.attribute}_${details.column}`
                     );
                   };
                   break;
@@ -933,7 +930,7 @@ module.exports = function(strapi) {
                     }
 
                     if (models.length === 0) {
-                      strapi.log.error('Impossible to register the `' + model + '` model.');
+                      strapi.log.error(`Impossible to register the '${model}' model.`);
                       strapi.log.error('The collection name cannot be found for the morphTo method.');
                       strapi.stop();
                     }