diff --git a/common/zlib/Makefile.am b/common/zlib/Makefile.am
index 4c51d2b..10b7ffc 100644
--- a/common/zlib/Makefile.am
+++ b/common/zlib/Makefile.am
@@ -1,6 +1,8 @@
 noinst_LTLIBRARIES = libz.la
 
-libz_la_SOURCES = adler32.c compress.c crc32.c deflate.c deflate.h \
-	gzio.c infblock.c infblock.h infcodes.c infcodes.h inffast.c \
-	inffast.h inffixed.h inflate.c inftrees.c inftrees.h infutil.c \
-	infutil.h trees.c trees.h uncompr.c zconf.h zlib.h zutil.c zutil.h
+HDRS = deflate.h infblock.h infcodes.h inffast.h inffixed.h inftrees.h \
+	infutil.h trees.h zconf.h zlib.h zutil.h
+
+libz_la_SOURCES = $(HDRS) adler32.c compress.c crc32.c deflate.c gzio.c \
+	infblock.c infcodes.c inffast.c inflate.c inftrees.c infutil.c \
+	trees.c uncompr.c