diff --git a/Makefile b/Makefile
index b26bc5a4..a1810c82 100644
--- a/Makefile
+++ b/Makefile
@@ -41,15 +41,21 @@ install: composer.lock yarn.lock
 	$(DOCKER_PHP) composer install --prefer-dist --no-interaction --no-progress --ansi
 	$(DOCKER_NODE) yarn install
 
-test:
+test: unit test-recursion.json test-recursion2.yaml test-empty-maps.json
+
+unit:
 	$(DOCKER_PHP) php $(PHPARGS) $(XPHPARGS) vendor/bin/phpunit --verbose --colors=always $(TESTCASE)
-	$(DOCKER_PHP) php $(PHPARGS) $(XPHPARGS) bin/php-openapi validate tests/spec/data/recursion.json
-	$(DOCKER_PHP) php $(PHPARGS) $(XPHPARGS) bin/php-openapi validate tests/spec/data/recursion2.yaml
+
+# test specific JSON files in tests/spec/data/
+# e.g. test-recursion will run validation on tests/spec/data/recursion.json
+test-%: tests/spec/data/%
+	$(DOCKER_PHP) php $(PHPARGS) $(XPHPARGS) bin/php-openapi validate $<
 
 lint: install
 	$(DOCKER_PHP) php $(PHPARGS) $(XPHPARGS) bin/php-openapi validate tests/spec/data/reference/playlist.json
 	$(DOCKER_PHP) php $(PHPARGS) $(XPHPARGS) bin/php-openapi validate tests/spec/data/recursion.json
 	$(DOCKER_PHP) php $(PHPARGS) $(XPHPARGS) bin/php-openapi validate tests/spec/data/recursion2.yaml
+	$(DOCKER_PHP) php $(PHPARGS) $(XPHPARGS) bin/php-openapi validate tests/spec/data/empty-maps.json
 	$(DOCKER_NODE) yarn run speccy lint tests/spec/data/reference/playlist.json
 	$(DOCKER_NODE) yarn run speccy lint tests/spec/data/recursion.json
 
diff --git a/src/SpecBaseObject.php b/src/SpecBaseObject.php
index 29f70b42..a86324bd 100644
--- a/src/SpecBaseObject.php
+++ b/src/SpecBaseObject.php
@@ -190,15 +190,23 @@ public function getSerializableData()
             if ($v instanceof SpecObjectInterface) {
                 $data[$k] = $v->getSerializableData();
             } elseif (is_array($v)) {
+                // test if php arrays should be represented as object in YAML/JSON
                 $toObject = false;
-                $j = 0;
-                foreach ($v as $i => $d) {
-                    if ($j++ !== $i) {
-                        $toObject = true;
-                    }
-                    if ($d instanceof SpecObjectInterface) {
-                        $data[$k][$i] = $d->getSerializableData();
+                if (!empty($v)) {
+                    // case 1: non-empty array should be an object if it does not contain
+                    // consecutive numeric keys
+                    $j = 0;
+                    foreach ($v as $i => $d) {
+                        if ($j++ !== $i) {
+                            $toObject = true;
+                        }
+                        if ($d instanceof SpecObjectInterface) {
+                            $data[$k][$i] = $d->getSerializableData();
+                        }
                     }
+                } elseif (isset($this->attributes()[$k]) && is_array($this->attributes()[$k]) && 2 === count($this->attributes()[$k])) {
+                    // case 2: Attribute type is an object (specified in attributes() by an array which specifies two items (key and value type)
+                    $toObject = true;
                 }
                 if ($toObject) {
                     $data[$k] = (object) $data[$k];
diff --git a/tests/spec/data/empty-maps.json b/tests/spec/data/empty-maps.json
new file mode 100644
index 00000000..51b1eee7
--- /dev/null
+++ b/tests/spec/data/empty-maps.json
@@ -0,0 +1,22 @@
+{
+  "openapi": "3.0.1",
+  "info": {
+    "title": "test",
+    "version": "1.0"
+  },
+  "paths": {
+    "/products": {
+      "description": "default",
+      "get": {
+        "responses": {
+          "200": {
+            "description": "Products",
+            "headers": {},
+            "content": {},
+            "links": {}
+          }
+        }
+      }
+    }
+  }
+}
\ No newline at end of file