diff --git a/packages/strapi-hook-bookshelf/lib/relations.js b/packages/strapi-hook-bookshelf/lib/relations.js
index 55b51a0ce6..0b8695510c 100644
--- a/packages/strapi-hook-bookshelf/lib/relations.js
+++ b/packages/strapi-hook-bookshelf/lib/relations.js
@@ -37,6 +37,16 @@ module.exports = {
 
   generateMatchStage: function (qb) {
     return (strapiModel, filters) => {
+      if (!filters) {
+        return undefined;
+      }
+
+      // 1st level deep filter
+      if (filters.where) {
+        this.generateMatchStage(qb)(strapiModel, { relations: filters.where });
+      }
+
+      // 2nd+ level deep filter
       _.forEach(filters.relations, (value, key) => {
         if (key !== 'relations') {
           const association = strapiModel.associations.find(a => a.alias === key);
diff --git a/packages/strapi-hook-mongoose/lib/relations.js b/packages/strapi-hook-mongoose/lib/relations.js
index 682a7a5adc..a6999233ce 100644
--- a/packages/strapi-hook-mongoose/lib/relations.js
+++ b/packages/strapi-hook-mongoose/lib/relations.js
@@ -101,6 +101,18 @@ module.exports = {
 
     let acc = [];
 
+    // 1st level deep filter
+    if (filters.where) {
+      acc.push(
+        ...generateMatchStage(
+          strapiModel,
+          { relations: filters.where },
+          { prefixPath }
+        )
+      );
+    }
+
+    // 2nd+ level deep filter
     _.forEach(filters.relations, (value, key) => {
       if (key !== 'relations') {
         const nextPrefixedPath = `${prefixPath}${key}.`;
diff --git a/packages/strapi-plugin-graphql/services/Query.js b/packages/strapi-plugin-graphql/services/Query.js
index 26c307c843..989e78e89d 100644
--- a/packages/strapi-plugin-graphql/services/Query.js
+++ b/packages/strapi-plugin-graphql/services/Query.js
@@ -32,7 +32,7 @@ module.exports = {
       if (_.isPlainObject(value)) {
         const flatObject = this.convertToQuery(value);
         _.forEach (flatObject, (_value, _key) => {
-          result[key + '.' + _key] = _value;
+          result[`${key}.${_key}`] = _value;
         });
       } else {
         result[key] = value;
diff --git a/packages/strapi-plugin-graphql/services/Resolvers.js b/packages/strapi-plugin-graphql/services/Resolvers.js
index dfbeb680e6..51235dc7c2 100644
--- a/packages/strapi-plugin-graphql/services/Resolvers.js
+++ b/packages/strapi-plugin-graphql/services/Resolvers.js
@@ -398,7 +398,7 @@ module.exports = {
               queryOpts.skip = convertedParams.start;
 
               switch (association.nature) {
-                case "manyToMany":
+                case "manyToMany": {
                   const arrayOfIds = (obj[association.alias] || []).map(
                     related => {
                       return related[ref.primaryKey] || related;
@@ -413,7 +413,7 @@ module.exports = {
                     ...where.where,
                   }).where;
                   break;
-                  // falls through
+                }
                 default:
                   // Where.
                   queryOpts.query = strapi.utils.models.convertParams(name, {
diff --git a/packages/strapi-plugin-users-permissions/config/queries/bookshelf.js b/packages/strapi-plugin-users-permissions/config/queries/bookshelf.js
index cf90842d72..860ac31e09 100644
--- a/packages/strapi-plugin-users-permissions/config/queries/bookshelf.js
+++ b/packages/strapi-plugin-users-permissions/config/queries/bookshelf.js
@@ -18,10 +18,9 @@ module.exports = {
         }
       }
     })
-    .fetchAll({
-      withRelated: populate || _.keys(_.groupBy(_.reject(this.associations, { autoPopulate: false }), 'alias'))
-    });
-
+      .fetchAll({
+        withRelated: populate || _.keys(_.groupBy(_.reject(this.associations, { autoPopulate: false }), 'alias'))
+      });
 
     return records ? records.toJSON() : records;
   },
diff --git a/packages/strapi-utils/lib/models.js b/packages/strapi-utils/lib/models.js
index ec80dc1658..de1545ad24 100644
--- a/packages/strapi-utils/lib/models.js
+++ b/packages/strapi-utils/lib/models.js
@@ -11,11 +11,6 @@ const path = require('path');
 const _ = require('lodash');
 const pluralize = require('pluralize');
 
-// Following this discussion https://stackoverflow.com/questions/18082/validate-decimal-numbers-in-javascript-isnumeric this function is the best implem to determine if a value is a valid number candidate
-const isNumeric = (value) => {
-  return !_.isObject(value) && !isNaN(parseFloat(value)) && isFinite(value);
-};
-
 // Constants
 const ORDERS = ['ASC', 'DESC'];