diff --git a/programs/psa/CMakeLists.txt b/programs/psa/CMakeLists.txt
index c5d0d28dd..fd8eeea78 100644
--- a/programs/psa/CMakeLists.txt
+++ b/programs/psa/CMakeLists.txt
@@ -9,7 +9,7 @@ if(DEV_MODE)
         OUTPUT
             ${CMAKE_CURRENT_BINARY_DIR}/psa_constant_names_generated.c
         COMMAND
-            ${PYTHON}
+            ${MBEDTLS_PYTHON_EXECUTABLE}
                 ${CMAKE_CURRENT_SOURCE_DIR}/../../scripts/generate_psa_constants.py
                 ${CMAKE_CURRENT_BINARY_DIR}
         WORKING_DIRECTORY
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index c88476968..0bd94baa2 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -19,6 +19,7 @@ file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/suites)
 # Get base names for generated files (starting at "suites/")
 execute_process(
     COMMAND
+        ${MBEDTLS_PYTHON_EXECUTABLE}
         ${CMAKE_CURRENT_SOURCE_DIR}/../tests/scripts/generate_psa_tests.py
         --list-for-cmake
         --directory suites