diff --git a/src/Makefile.am b/src/Makefile.am
index 14f1b8e4d93..9ad46121904 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -48,7 +48,7 @@ AUTH_LIBS= auth/libauth.la
 AUTH_ACL_LIBS= auth/libacls.la
 endif
 
-SUBDIRS	+= \
+SUBDIRS += \
 	http \
 	ip \
 	icmp \