diff --git a/src/Makefile.am b/src/Makefile.am
index cd75fdf4..bba90628 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -129,7 +129,7 @@ NGHTTPX_SRCS = \
 	shrpx_process.h \
 	shrpx_signal.cc shrpx_signal.h \
 	shrpx_router.cc shrpx_router.h \
-	buffer.h memchunk.h template.h
+	buffer.h memchunk.h template.h allocator.h
 
 if HAVE_SPDYLAY
 NGHTTPX_SRCS += shrpx_spdy_upstream.cc shrpx_spdy_upstream.h