diff --git a/tests/python/CMakeLists.txt b/tests/python/CMakeLists.txt
index ceed2ca4d09..e03d8c065e7 100644
--- a/tests/python/CMakeLists.txt
+++ b/tests/python/CMakeLists.txt
@@ -513,30 +513,34 @@ add_test(
 )
 endif()
 
+# Run Python script outside Blender.
+function(add_python_test testname testscript)
+	if(MSVC)
+		add_test(
+			NAME ${testname}
+			COMMAND
+				"$<TARGET_FILE_DIR:blender>/${BLENDER_VERSION_MAJOR}.${BLENDER_VERSION_MINOR}/python/bin/python$<$<CONFIG:Debug>:_d>"
+				${testscript} ${ARGN}
+		)
+	else()
+		add_test(
+			NAME ${testname}
+			COMMAND ${testscript} ${ARGN}
+		)
+	endif()
+endfunction()
+
 if(WITH_CYCLES)
 	if(OPENIMAGEIO_IDIFF AND EXISTS "${TEST_SRC_DIR}/cycles/ctests/shader")
 		macro(add_cycles_render_test subject)
-			if(MSVC)
-				add_test(
-					NAME cycles_${subject}_test
-					COMMAND
-						"$<TARGET_FILE_DIR:blender>/${BLENDER_VERSION_MAJOR}.${BLENDER_VERSION_MINOR}/python/bin/python$<$<CONFIG:Debug>:_d>"
-						${CMAKE_CURRENT_LIST_DIR}/cycles_render_tests.py
-					-blender "$<TARGET_FILE:blender>"
-					-testdir "${TEST_SRC_DIR}/cycles/ctests/${subject}"
-					-idiff "${OPENIMAGEIO_IDIFF}"
-					-outdir "${TEST_OUT_DIR}/cycles"
-				)
-			else()
-				add_test(
-					NAME cycles_${subject}_test
-					COMMAND ${CMAKE_CURRENT_LIST_DIR}/cycles_render_tests.py
-					-blender "$<TARGET_FILE:blender>"
-					-testdir "${TEST_SRC_DIR}/cycles/ctests/${subject}"
-					-idiff "${OPENIMAGEIO_IDIFF}"
-					-outdir "${TEST_OUT_DIR}/cycles"
-				)
-			endif()
+			add_python_test(
+				cycles_${subject}_test
+				${CMAKE_CURRENT_LIST_DIR}/cycles_render_tests.py
+				-blender "$<TARGET_FILE:blender>"
+				-testdir "${TEST_SRC_DIR}/cycles/ctests/${subject}"
+				-idiff "${OPENIMAGEIO_IDIFF}"
+				-outdir "${TEST_OUT_DIR}/cycles"
+			)
 		endmacro()
 		if(WITH_OPENGL_RENDER_TESTS)
 			add_cycles_render_test(opengl)
@@ -564,44 +568,23 @@ endif()
 
 if(WITH_OPENGL_DRAW_TESTS)
 	if(OPENIMAGEIO_IDIFF AND EXISTS "${TEST_SRC_DIR}/opengl")
-		macro(add_opengl_draw_test subject)
-			if(MSVC)
-				add_test(
-					NAME opengl_draw_${subject}_test
-					COMMAND
-						"$<TARGET_FILE_DIR:blender>/${BLENDER_VERSION_MAJOR}.${BLENDER_VERSION_MINOR}/python/bin/python$<$<CONFIG:Debug>:_d>"
+		# Use all test folders
+		file(GLOB children RELATIVE ${TEST_SRC_DIR} ${TEST_SRC_DIR}/*)
+		foreach(child ${children})
+			if(IS_DIRECTORY ${TEST_SRC_DIR}/${child})
+				file(GLOB blends ${TEST_SRC_DIR}/${child}/*.blend)
+				if(blends)
+					add_python_test(
+						opengl_draw_${child}_test
 						${CMAKE_CURRENT_LIST_DIR}/opengl_draw_tests.py
-					-blender "$<TARGET_FILE:blender>"
-					-testdir "${TEST_SRC_DIR}/${subject}"
-					-idiff "${OPENIMAGEIO_IDIFF}"
-					-outdir "${TEST_OUT_DIR}/opengl_draw"
-				)
-			else()
-				add_test(
-					NAME opengl_draw_${subject}_test
-					COMMAND ${CMAKE_CURRENT_LIST_DIR}/opengl_draw_tests.py
-					-blender "$<TARGET_FILE:blender>"
-					-testdir "${TEST_SRC_DIR}/${subject}"
-					-idiff "${OPENIMAGEIO_IDIFF}"
-					-outdir "${TEST_OUT_DIR}/opengl_draw"
-				)
-			endif()
-		endmacro()
-
-		function(add_opengl_draw_tests)
-			# Use all test folders
-			file(GLOB children RELATIVE ${TEST_SRC_DIR} ${TEST_SRC_DIR}/*)
-			foreach(child ${children})
-				if(IS_DIRECTORY ${TEST_SRC_DIR}/${child})
-					file(GLOB blends ${TEST_SRC_DIR}/${child}/*.blend)
-					if(blends)
-						add_opengl_draw_test(${child})
-					endif()
+						-blender "$<TARGET_FILE:blender>"
+						-testdir "${TEST_SRC_DIR}/${child}"
+						-idiff "${OPENIMAGEIO_IDIFF}"
+						-outdir "${TEST_OUT_DIR}/opengl_draw"
+					)
 				endif()
-			endforeach()
-		endfunction()
-
-		add_opengl_draw_tests()
+			endif()
+		endforeach()
 	else()
 		MESSAGE(STATUS "Disabling OpenGL tests because tests folder does not exist")
 	endif()
@@ -616,26 +599,13 @@ if(WITH_ALEMBIC)
 	get_filename_component(real_include_dir ${ALEMBIC_INCLUDE_DIR} REALPATH)
 	get_filename_component(ALEMBIC_ROOT_DIR ${real_include_dir} DIRECTORY)
 
-	if(MSVC)
-		# FIXME, de-duplicate.
-		add_test(
-			NAME alembic_tests
-			COMMAND
-				"$<TARGET_FILE_DIR:blender>/${BLENDER_VERSION_MAJOR}.${BLENDER_VERSION_MINOR}/python/bin/python$<$<CONFIG:Debug>:_d>"
-				${CMAKE_CURRENT_LIST_DIR}/alembic_tests.py
-			--blender "$<TARGET_FILE:blender>"
-			--testdir "${TEST_SRC_DIR}/alembic"
-			--alembic-root "${ALEMBIC_ROOT_DIR}"
-		)
-	else()
-		add_test(
-			NAME alembic_tests
-			COMMAND ${CMAKE_CURRENT_LIST_DIR}/alembic_tests.py
-			--blender "$<TARGET_FILE:blender>"
-			--testdir "${TEST_SRC_DIR}/alembic"
-			--alembic-root "${ALEMBIC_ROOT_DIR}"
-		)
-	endif()
+	add_python_test(
+		alembic_tests
+		${CMAKE_CURRENT_LIST_DIR}/alembic_tests.py
+		--blender "$<TARGET_FILE:blender>"
+		--testdir "${TEST_SRC_DIR}/alembic"
+		--alembic-root "${ALEMBIC_ROOT_DIR}"
+	)
 
 	add_test(
 		NAME script_alembic_import