diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index d36362ebb..b1c72b76a 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -211,10 +211,10 @@ foreach(target ${test_targets})
 
   # Always write the output file directly into the 'tests' directory (even on MSVC)
   if(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
-    set_target_properties(${target} PROPERTIES LIBRARY_OUTPUT_DIRECTORY ${testdir})
+    set_target_properties(${target} PROPERTIES LIBRARY_OUTPUT_DIRECTORY "${testdir}")
     foreach(config ${CMAKE_CONFIGURATION_TYPES})
       string(TOUPPER ${config} config)
-      set_target_properties(${target} PROPERTIES LIBRARY_OUTPUT_DIRECTORY_${config} ${testdir})
+      set_target_properties(${target} PROPERTIES LIBRARY_OUTPUT_DIRECTORY_${config} "${testdir}")
     endforeach()
   endif()
 endforeach()
diff --git a/tests/test_embed/CMakeLists.txt b/tests/test_embed/CMakeLists.txt
index 8b4f1f843..c5aa7c6c5 100644
--- a/tests/test_embed/CMakeLists.txt
+++ b/tests/test_embed/CMakeLists.txt
@@ -17,25 +17,29 @@ add_executable(test_embed
   catch.cpp
   test_interpreter.cpp
 )
-target_include_directories(test_embed PRIVATE ${CATCH_INCLUDE_DIR})
+target_include_directories(test_embed PRIVATE "${CATCH_INCLUDE_DIR}")
 pybind11_enable_warnings(test_embed)
 
 if(NOT CMAKE_VERSION VERSION_LESS 3.0)
   target_link_libraries(test_embed PRIVATE pybind11::embed)
 else()
-  target_include_directories(test_embed PRIVATE ${PYBIND11_INCLUDE_DIR} ${PYTHON_INCLUDE_DIRS})
-  target_compile_options(test_embed PRIVATE ${PYBIND11_CPP_STANDARD})
-  target_link_libraries(test_embed PRIVATE ${PYTHON_LIBRARIES})
+  target_include_directories(test_embed PRIVATE "${PYBIND11_INCLUDE_DIR}" "${PYTHON_INCLUDE_DIRS}")
+  target_compile_options(test_embed PRIVATE "${PYBIND11_CPP_STANDARD}")
+  target_link_libraries(test_embed PRIVATE "${PYTHON_LIBRARIES}")
 endif()
 
 find_package(Threads REQUIRED)
 target_link_libraries(test_embed PUBLIC ${CMAKE_THREAD_LIBS_INIT})
 
 add_custom_target(cpptest COMMAND $<TARGET_FILE:test_embed>
-                  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
+                  WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
 
 pybind11_add_module(external_module THIN_LTO external_module.cpp)
-set_target_properties(external_module PROPERTIES LIBRARY_OUTPUT_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
+set_target_properties(external_module PROPERTIES LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
+foreach(config ${CMAKE_CONFIGURATION_TYPES})
+  string(TOUPPER ${config} config)
+  set_target_properties(external_module PROPERTIES LIBRARY_OUTPUT_DIRECTORY_${config} "${CMAKE_CURRENT_SOURCE_DIR}")
+endforeach()
 add_dependencies(cpptest external_module)
 
 add_dependencies(check cpptest)