diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 132edbfb..9a5fc53a 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -197,7 +197,7 @@ if(NOT CMAKE_VERSION VERSION_LESS 3.1)
 
     set(build_options "-DCMAKE_PREFIX_PATH=${PROJECT_BINARY_DIR}/mock_install"
                       "-DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}"
-                      "-DPYTHON_EXECUTABLE=${PYTHON_EXECUTABLE}"
+                      "-DPYTHON_EXECUTABLE:FILEPATH=${PYTHON_EXECUTABLE}"
                       "-DPYBIND11_CPP_STANDARD=${PYBIND11_CPP_STANDARD}")
     if(NOT ARG_INSTALL)
       list(APPEND build_options "-DPYBIND11_PROJECT_DIR=${PROJECT_SOURCE_DIR}")