diff --git a/tests/Makefile.include b/tests/Makefile.include
index 3a0524ce74..ceaf3f0d6e 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -138,6 +138,7 @@ check:
 ifeq ($(CONFIG_TOOLS)$(CONFIG_POSIX),yy)
 QEMU_IOTESTS_HELPERS-$(CONFIG_LINUX) = tests/qemu-iotests/socket_scm_helper$(EXESUF)
 check: check-block
+export PYTHON
 check-block: $(SRC_PATH)/tests/check-block.sh qemu-img$(EXESUF) \
 		qemu-io$(EXESUF) qemu-nbd$(EXESUF) $(QEMU_IOTESTS_HELPERS-y) \
 		$(filter qemu-system-%, $(ninja-targets))