diff --git a/tools/Makefile b/tools/Makefile
index 9e28027835..4906fdbc23 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -218,9 +218,9 @@ subdir-all-qemu-xen-dir: qemu-xen-dir-find
 	mkdir -p qemu-xen-build; \
 	cd qemu-xen-build; \
 	if $$source/scripts/tracetool.py --check-backend --backend log ; then \
-		enable_trace_backend='--enable-trace-backend=log'; \
+		enable_trace_backend="--enable-trace-backends=log"; \
 	elif $$source/scripts/tracetool.py --check-backend --backend stderr ; then \
-		enable_trace_backend='--enable-trace-backend=stderr'; \
+		enable_trace_backend='--enable-trace-backends=stderr'; \
 	else \
 		enable_trace_backend='' ; \
 	fi ; \