diff --git a/Makefile b/Makefile
index 0e21a49..e0828fe 100644
--- a/Makefile
+++ b/Makefile
@@ -101,7 +101,7 @@
 
 -include */.*.d */*/.*.d
 
-all: directories $(shell cd $(SRCDIR) && git rev-parse --verify --short=8 HEAD >$(PWD)/build-head 2>/dev/null)
+all: directories $(shell (cd $(SRCDIR) && git rev-parse --verify --short=8 HEAD) >build-head 2>/dev/null)
 
 standalone: all
 	@scripts/mkstandalone.sh