diff --git a/gc-benchmarks/local.mk b/gc-benchmarks/local.mk
index 06fb598ab..144424b29 100644
--- a/gc-benchmarks/local.mk
+++ b/gc-benchmarks/local.mk
@@ -19,7 +19,7 @@
 ##   write to the Free Software Foundation, Inc., 51 Franklin Street,
 ##   Fifth Floor, Boston, MA 02110-1301 USA
 
-EXTRA_DIST =					\
+EXTRA_DIST +=					\
   %D%/gc-profile.scm				\
   %D%/gcbench.scm				\
   %D%/guile-test.scm				\