diff --git a/os/Makefile.in b/os/Makefile.in
index 00fae216e6..8d1105c0f2 100644
--- a/os/Makefile.in
+++ b/os/Makefile.in
@@ -1,4 +1,4 @@
 
-SUBDIRS = $(top_srcdir)/$(OS_DIR)
+SUBDIRS = $(top_builddir)/$(OS_DIR)
 
 include $(top_srcdir)/build/rules.mk