diff --git a/src/SettingStore.php b/src/SettingStore.php
index d5e8286..3375158 100644
--- a/src/SettingStore.php
+++ b/src/SettingStore.php
@@ -231,7 +231,7 @@ public function load($force = false)
 		if (!$this->loaded || $force) {
 			$this->data = $this->readData();
             $this->persistedData = $this->data;
-            $this->data = array_merge($this->updatedData, $this->data);
+            $this->data = $this->updatedData + $this->data;
             $this->loaded = true;
 		}
 	}
diff --git a/tests/functional/AbstractFunctionalTest.php b/tests/functional/AbstractFunctionalTest.php
index 041707a..954446f 100644
--- a/tests/functional/AbstractFunctionalTest.php
+++ b/tests/functional/AbstractFunctionalTest.php
@@ -145,4 +145,15 @@ public function defaults_are_respected()
 		$this->assertStoreEquals($store, ['foo' => 'bar']);
 		$this->assertStoreKeyEquals($store, ['foo', 'bar'], ['foo' => 'bar', 'bar' => 'default']);
 	}
+
+    /** @test */
+    public function numeric_keys_are_retrieved_correctly()
+    {
+        $store = $this->getStore();
+        $store->set('1234', 'foo');
+        $store->set('9876', 'bar');
+        $store->load(true);
+        $this->assertStoreEquals($store, ['1234' => 'foo', '9876' => 'bar']);
+        $this->assertStoreKeyEquals($store, ['1234', '9876'], ['1234' => 'foo', '9876' => 'bar']);
+    }
 }