diff --git a/CMakeLists.txt b/CMakeLists.txt
index 46dfd73..1b27cf2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -382,7 +382,7 @@ if (BUILD_TESTING AND NOT_SUBPROJECT)
     set_tests_properties(NoTest PROPERTIES PASS_REGULAR_EXPRESSION "No test cases matched")
 
     # AppVeyor has a Python 2.7 in path, but doesn't have .py files as autorunnable
-    add_test(NAME ApprovalTests COMMAND python ${CMAKE_CURRENT_SOURCE_DIR}/scripts/approvalTests.py $<TARGET_FILE:SelfTest>)
+    add_test(NAME ApprovalTests COMMAND python3 ${CMAKE_CURRENT_SOURCE_DIR}/scripts/approvalTests.py $<TARGET_FILE:SelfTest>)
     set_tests_properties(ApprovalTests PROPERTIES FAIL_REGULAR_EXPRESSION "Results differed")
 
     if (CATCH_USE_VALGRIND)