diff --git a/src/packages/database/query/runner/utils/build-results.js b/src/packages/database/query/runner/utils/build-results.js
index 6db66fd1..ae65915f 100644
--- a/src/packages/database/query/runner/utils/build-results.js
+++ b/src/packages/database/query/runner/utils/build-results.js
@@ -108,7 +108,7 @@ export default async function buildResults<T: Model>({
         .reduce((r, entry) => {
           let [key, value] = entry;
 
-          if (!value && pkPattern.test(key)) {
+          if (value == null && pkPattern.test(key)) {
             return r;
           } else if (key.indexOf('.') >= 0) {
             const [a, b] = key.split('.');
diff --git a/src/packages/serializer/index.js b/src/packages/serializer/index.js
index 245f44eb..096c566c 100644
--- a/src/packages/serializer/index.js
+++ b/src/packages/serializer/index.js
@@ -616,7 +616,7 @@ class Serializer<T: Model> {
                   })
                 )
               };
-            } else if (related && related.id) {
+            } else if (related && related.id != null) {
               return this.formatRelationship({
                 domain,
                 included,