diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 0b4f2e1..4dd1fe0 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -58,14 +58,16 @@ list(APPEND CMAKE_MODULE_PATH ${Catch2_SOURCE_DIR}/extras)
 include(Catch)
 catch_discover_tests(vk-bootstrap-test)
 
-# Test add_subdirectory support using fetch content vulkan headers
-add_test(NAME integration.add_subdirectory.fetch_content_vulkan_headers
-    COMMAND ${CMAKE_CTEST_COMMAND}
-        --build-and-test ${CMAKE_CURRENT_LIST_DIR}/integration
-                         ${CMAKE_CURRENT_BINARY_DIR}/add_subdirectory/fetch_content_vulkan_headers
-        --build-generator ${CMAKE_GENERATOR}
-        --build-options -DADD_SUBDIRECTORY_TESTING=ON -DVULKAN_HEADER_VERSION_GIT_TAG=${VK_BOOTSTRAP_SOURCE_HEADER_VERSION_GIT_TAG}
-)
+# Commented out for nixpkgs due to external dependencies.
+#
+# # Test add_subdirectory support using fetch content vulkan headers
+# add_test(NAME integration.add_subdirectory.fetch_content_vulkan_headers
+#     COMMAND ${CMAKE_CTEST_COMMAND}
+#         --build-and-test ${CMAKE_CURRENT_LIST_DIR}/integration
+#                          ${CMAKE_CURRENT_BINARY_DIR}/add_subdirectory/fetch_content_vulkan_headers
+#         --build-generator ${CMAKE_GENERATOR}
+#         --build-options -DADD_SUBDIRECTORY_TESTING=ON -DVULKAN_HEADER_VERSION_GIT_TAG=${VK_BOOTSTRAP_SOURCE_HEADER_VERSION_GIT_TAG}
+# )
 
  get_target_property(vulkan_headers_include_dir Vulkan::Headers INTERFACE_INCLUDE_DIRECTORIES)
 
@@ -105,7 +107,7 @@ if (VulkanHeaders_FOUND)
                 --build-and-test ${CMAKE_CURRENT_LIST_DIR}/integration
                                 ${CMAKE_CURRENT_BINARY_DIR}/find_package/find_package_vulkan_headers
                 --build-generator ${CMAKE_GENERATOR}
-                --build-options -DFIND_PACKAGE_TESTING=ON "-DCMAKE_PREFIX_PATH=${vulkan_headers_install_dir};${test_install_dir}"
+                --build-options -DFIND_PACKAGE_TESTING=ON "-DCMAKE_PREFIX_PATH=${vulkan_headers_install_dir};${test_install_dir};${CMAKE_INSTALL_PREFIX}"
         )
 
         set_tests_properties(integration.find_package.find_package_vulkan_headers PROPERTIES DEPENDS integration.install)