diff --git a/openbsc/tests/gbproxy/Makefile.am b/openbsc/tests/gbproxy/Makefile.am
index 18d77a8..2dd66df 100644
--- a/openbsc/tests/gbproxy/Makefile.am
+++ b/openbsc/tests/gbproxy/Makefile.am
@@ -1,27 +1,54 @@
-AM_CPPFLAGS = $(all_includes) -I$(top_srcdir)/include
-AM_CFLAGS=-Wall -ggdb3 $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGSM_CFLAGS) $(LIBOSMOABIS_CFLAGS)
-AM_LDFLAGS = $(COVERAGE_LDFLAGS)
+AM_CPPFLAGS = \
+	$(all_includes) \
+	-I$(top_srcdir)/include \
+	$(NULL)
 
-EXTRA_DIST = gbproxy_test.ok
+AM_CFLAGS = \
+	-Wall \
+	-ggdb3 \
+	$(LIBOSMOCORE_CFLAGS) \
+	$(LIBOSMOGSM_CFLAGS) \
+	$(LIBOSMOABIS_CFLAGS) \
+	$(NULL)
 
-noinst_PROGRAMS = gbproxy_test
+AM_LDFLAGS = \
+	$(COVERAGE_LDFLAGS) \
+	$(NULL)
 
-gbproxy_test_SOURCES = gbproxy_test.c
+EXTRA_DIST = \
+	gbproxy_test.ok \
+	$(NULL)
+
+noinst_PROGRAMS = \
+	gbproxy_test \
+	$(NULL)
+
+gbproxy_test_SOURCES = \
+	gbproxy_test.c \
+	$(NULL)
+
 gbproxy_test_LDFLAGS = \
-	     -Wl,--wrap=RAND_bytes
+	-Wl,--wrap=RAND_bytes \
+	$(NULL)
+
 gbproxy_test_LDADD = \
-			$(top_builddir)/src/gprs/gb_proxy.o \
-			$(top_builddir)/src/gprs/gb_proxy_patch.o \
-			$(top_builddir)/src/gprs/gb_proxy_peer.o \
-			$(top_builddir)/src/gprs/gb_proxy_tlli.o \
-			$(top_builddir)/src/gprs/gprs_gb_parse.o \
-			$(top_builddir)/src/gprs/gprs_llc_parse.o \
-			$(top_builddir)/src/gprs/crc24.o \
-			$(top_builddir)/src/gprs/gprs_utils.o \
-			$(top_builddir)/src/libcommon/libcommon.a \
-			$(top_builddir)/src/libbsc/libbsc.a \
-			$(top_builddir)/src/libtrau/libtrau.a \
-			$(LIBOSMOCORE_LIBS) $(LIBOSMOGB_LIBS) \
-			$(LIBOSMOGSM_LIBS)  $(LIBOSMOVTY_LIBS) \
-			$(LIBOSMOABIS_LIBS) $(LIBRARY_DL) \
-			$(LIBCRYPTO_LIBS) -lrt
+	$(top_builddir)/src/gprs/gb_proxy.o \
+	$(top_builddir)/src/gprs/gb_proxy_patch.o \
+	$(top_builddir)/src/gprs/gb_proxy_peer.o \
+	$(top_builddir)/src/gprs/gb_proxy_tlli.o \
+	$(top_builddir)/src/gprs/gprs_gb_parse.o \
+	$(top_builddir)/src/gprs/gprs_llc_parse.o \
+	$(top_builddir)/src/gprs/crc24.o \
+	$(top_builddir)/src/gprs/gprs_utils.o \
+	$(top_builddir)/src/libcommon/libcommon.a \
+	$(top_builddir)/src/libbsc/libbsc.a \
+	$(top_builddir)/src/libtrau/libtrau.a \
+	$(LIBOSMOCORE_LIBS) \
+	$(LIBOSMOGB_LIBS) \
+	$(LIBOSMOGSM_LIBS) \
+	$(LIBOSMOVTY_LIBS) \
+	$(LIBOSMOABIS_LIBS) \
+	$(LIBRARY_DL) \
+	$(LIBCRYPTO_LIBS) \
+	-lrt \
+	$(NULL)