diff --git a/lib/index.js b/lib/index.js
index 2f7419a..fe47dc9 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -257,68 +257,70 @@ exports.setSchema = function (schema) {
 
         foundObjects.get(type).set(JSON.stringify(obj.id), obj);
 
-        // fetch all relations
         var subTasks = [];
-        Object.keys(typeInfo.relations || {}).forEach(function (field) {
-          var relationDef = typeInfo.relations[field];
-          var relationType = Object.keys(relationDef)[0];
-          var relatedType = relationDef[relationType];
-          if (typeof relatedType !== 'string') {
-            var relationOptions = relatedType.options;
-            var async = idOrIds && idOrIds.async;
-            if (async || (relationOptions && relationOptions.async && (async === undefined))) {
-              return;
-            }
-            relatedType = relatedType.type;
-          }
-          if (relationType === 'belongsTo') {
-            var relatedId = obj[field];
-            if (typeof relatedId !== 'undefined') {
-              subTasks.push(Promise.resolve().then(function () {
-
-                // short-circuit if it's already in the foundObjects
-                // else we could get caught in an infinite loop
-                if (foundObjects.has(relatedType) &&
-                    foundObjects.get(relatedType).has(JSON.stringify(relatedId))) {
-                  return;
-                }
-
-                // signal that we need to fetch it
-                return {
-                  relatedType: relatedType,
-                  relatedIds: [relatedId]
-                };
-              }));
+
+        if (!idOrIds || !idOrIds.async) {
+          // fetch all relations
+          Object.keys(typeInfo.relations || {}).forEach(function (field) {
+            var relationDef = typeInfo.relations[field];
+            var relationType = Object.keys(relationDef)[0];
+            var relatedType = relationDef[relationType];
+            if (typeof relatedType !== 'string') {
+              var relationOptions = relatedType.options;
+              if (relationOptions && relationOptions.async && typeof idOrIds === 'undefined') {
+                return;
+              }
+              relatedType = relatedType.type;
             }
-          } else { // hasMany
-            var relatedIds = extend(true, [], obj[field]);
-            if (typeof relatedIds !== 'undefined' && relatedIds.length) {
-              subTasks.push(Promise.resolve().then(function () {
-
-                // filter out all ids that are already in the foundObjects
-                for (var i = relatedIds.length - 1; i >= 0; i--) {
-                  var relatedId = relatedIds[i];
+            if (relationType === 'belongsTo') {
+              var relatedId = obj[field];
+              if (typeof relatedId !== 'undefined') {
+                subTasks.push(Promise.resolve().then(function () {
+
+                  // short-circuit if it's already in the foundObjects
+                  // else we could get caught in an infinite loop
                   if (foundObjects.has(relatedType) &&
                       foundObjects.get(relatedType).has(JSON.stringify(relatedId))) {
-                    delete relatedIds[i];
+                    return;
                   }
-                }
-                relatedIds = relatedIds.filter(function (relatedId) {
-                  return typeof relatedId !== 'undefined';
-                });
-
-                // just return the ids and the types. We'll find them all
-                // in a single bulk operation in order to minimize HTTP requests
-                if (relatedIds.length) {
+
+                  // signal that we need to fetch it
                   return {
                     relatedType: relatedType,
-                    relatedIds: relatedIds
+                    relatedIds: [relatedId]
                   };
-                }
-              }));
+                }));
+              }
+            } else { // hasMany
+              var relatedIds = extend(true, [], obj[field]);
+              if (typeof relatedIds !== 'undefined' && relatedIds.length) {
+                subTasks.push(Promise.resolve().then(function () {
+
+                  // filter out all ids that are already in the foundObjects
+                  for (var i = relatedIds.length - 1; i >= 0; i--) {
+                    var relatedId = relatedIds[i];
+                    if (foundObjects.has(relatedType) &&
+                        foundObjects.get(relatedType).has(JSON.stringify(relatedId))) {
+                      delete relatedIds[i];
+                    }
+                  }
+                  relatedIds = relatedIds.filter(function (relatedId) {
+                    return typeof relatedId !== 'undefined';
+                  });
+
+                  // just return the ids and the types. We'll find them all
+                  // in a single bulk operation in order to minimize HTTP requests
+                  if (relatedIds.length) {
+                    return {
+                      relatedType: relatedType,
+                      relatedIds: relatedIds
+                    };
+                  }
+                }));
+              }
             }
-          }
-        });
+          });
+        }
         return Promise.all(subTasks);
       });
       return Promise.all(tasks);
diff --git a/test/test.js b/test/test.js
index e60bfcf..079120b 100644
--- a/test/test.js
+++ b/test/test.js
@@ -1990,7 +1990,7 @@ function tests(dbName, dbType) {
           singular: 'author',
           plural: 'authors',
           relations: {
-            books: {hasMany: {type: 'books', options: {async: false}}}
+            books: {hasMany: 'books'}
           }
         },
         {