diff --git a/Makefile b/Makefile
index 9bbea7196..3a799af7f 100644
--- a/Makefile
+++ b/Makefile
@@ -263,7 +263,7 @@ ifeq ($(PYTEST),)
 	exit 1
 else
 # Explicitly hand DEVELOPER and VALGRIND so you can override on make cmd line.
-	PYTHONPATH=`pwd`/contrib/pyln-client:$$PYTHONPATH TEST_DEBUG=1 DEVELOPER=$(DEVELOPER) VALGRIND=$(VALGRIND) $(PYTEST) tests/ $(PYTEST_OPTS)
+	PYTHONPATH=`pwd`/contrib/pyln-client:`pwd`/contrib/pyln-testing:$$PYTHONPATH TEST_DEBUG=1 DEVELOPER=$(DEVELOPER) VALGRIND=$(VALGRIND) $(PYTEST) tests/ $(PYTEST_OPTS)
 endif
 
 # Keep includes in alpha order.