diff --git a/src/Makefile.am b/src/Makefile.am
index 2258bc3ed6e8133e57f8daf39c4e1801a427c5b9..b431cf269975db2bcbf8d475eb547eca6d208f1c 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -67,6 +67,10 @@ AM_LDFLAGS = \
 AUTOMAKE_OPTIONS = foreign 1.5
 
 # pass most important options when "make distcheck" is used
-DISTCHECK_CONFIGURE_FLAGS = --with-dune-common=$(DUNE_COMMON_ROOT) --with-dune-fufem=$(DUNE_FUFEM_ROOT) --with-dune-tnnmg=$(DUNE_TNNMG_ROOT)  CXX="$(CXX)" CC="$(CC)"
+DISTCHECK_CONFIGURE_FLAGS = \
+	--with-dune-common=$(DUNE_COMMON_ROOT) \
+	--with-dune-fufem=$(DUNE_FUFEM_ROOT) \
+	--with-dune-tnnmg=$(DUNE_TNNMG_ROOT) \
+	CXX="$(CXX)" CC="$(CC)"
 
 include $(top_srcdir)/am/global-rules