diff --git a/openbsc/src/libcommon/Makefile.am b/openbsc/src/libcommon/Makefile.am
index 75f40ee..6cfebc2 100644
--- a/openbsc/src/libcommon/Makefile.am
+++ b/openbsc/src/libcommon/Makefile.am
@@ -1,9 +1,29 @@
-AM_CPPFLAGS = $(all_includes) -I$(top_srcdir)/include -I$(top_builddir)
-AM_CFLAGS=-Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGSM_CFLAGS) \
-	$(LIBOSMOVTY_CFLAGS) $(LIBOSMOABIS_CFLAGS) $(COVERAGE_CFLAGS)
+AM_CPPFLAGS = \
+	$(all_includes) \
+	-I$(top_srcdir)/include \
+	-I$(top_builddir) \
+	$(NULL)
 
-noinst_LIBRARIES = libcommon.a
+AM_CFLAGS = \
+	-Wall \
+	$(LIBOSMOCORE_CFLAGS) \
+	$(LIBOSMOGSM_CFLAGS) \
+	$(LIBOSMOVTY_CFLAGS) \
+	$(LIBOSMOABIS_CFLAGS) \
+	$(COVERAGE_CFLAGS) \
+	$(NULL)
 
-libcommon_a_SOURCES = bsc_version.c common_vty.c debug.c gsm_data.c \
-		      gsm_data_shared.c socket.c talloc_ctx.c \
-		      gsm_subscriber_base.c
+noinst_LIBRARIES = \
+	libcommon.a \
+	$(NULL)
+
+libcommon_a_SOURCES = \
+	bsc_version.c \
+	common_vty.c \
+	debug.c \
+	gsm_data.c \
+	gsm_data_shared.c \
+	socket.c \
+	talloc_ctx.c \
+	gsm_subscriber_base.c \
+	$(NULL)