diff --git a/test/CoreTest.cpp b/test/CoreTest.cpp
index 095e95e868..90ac4e8cb7 100644
--- a/test/CoreTest.cpp
+++ b/test/CoreTest.cpp
@@ -300,7 +300,7 @@ TEST_CASE("custom_hierarchies", "[core]")
 
 TEST_CASE("custom_hierarchies_no_rw", "[core]")
 {
-    std::string filePath = "../samples/custom_hierarchies.bp";
+    std::string filePath = "../samples/custom_hierarchies.json";
     Series write(filePath, Access::CREATE);
     write.setMeshesPath(std::vector<std::string>{".*/meshes/"});
     write.iterations[0]["custom"]["hierarchy"];