diff --git a/src/interface/Makefile.inc.am b/src/interface/Makefile.inc.am
index 7353bc4c82..34acdb7566 100644
--- a/src/interface/Makefile.inc.am
+++ b/src/interface/Makefile.inc.am
@@ -9,7 +9,8 @@ INTERFACE_DRIVER_NETCF_SOURCES = interface/interface_backend_netcf.c
 INTERFACE_DRIVER_UDEV_SOURCES = interface/interface_backend_udev.c
 
 DRIVER_SOURCE_FILES += $(addprefix $(srcdir)/,$(INTERFACE_DRIVER_SOURCES))
-STATEFUL_DRIVER_SOURCE_FILES += $(addprefix $(srcdir)/,$(INTERFACE_DRIVER_SOURCES))
+STATEFUL_DRIVER_SOURCE_FILES += \
+	$(addprefix $(srcdir)/,$(INTERFACE_DRIVER_SOURCES))
 
 EXTRA_DIST += \
 	$(INTERFACE_DRIVER_SOURCES) \
diff --git a/src/network/Makefile.inc.am b/src/network/Makefile.inc.am
index 354c130f35..1cef1c7bce 100644
--- a/src/network/Makefile.inc.am
+++ b/src/network/Makefile.inc.am
@@ -17,7 +17,9 @@ NETWORK_LEASES_HELPER_SOURCES = \
 	$(NULL)
 
 DRIVER_SOURCE_FILES += $(addprefix $(srcdir)/,$(NETWORK_DRIVER_SOURCES))
-STATEFUL_DRIVER_SOURCE_FILES += $(addprefix $(srcdir)/,$(NETWORK_DRIVER_SOURCES))
+STATEFUL_DRIVER_SOURCE_FILES += \
+	$(addprefix $(srcdir)/,$(NETWORK_DRIVER_SOURCES))
+
 EXTRA_DIST += \
 	$(NETWORK_DRIVER_SOURCES) \
 	$(NETWORK_DRIVER_PLATFORM_INC) \
diff --git a/src/nwfilter/Makefile.inc.am b/src/nwfilter/Makefile.inc.am
index 7b57df3813..b51c8a5cda 100644
--- a/src/nwfilter/Makefile.inc.am
+++ b/src/nwfilter/Makefile.inc.am
@@ -19,7 +19,9 @@ NWFILTER_DRIVER_SOURCES = \
 	$(NULL)
 
 DRIVER_SOURCE_FILES += $(addprefix $(srcdir)/,$(NWFILTER_DRIVER_SOURCES))
-STATEFUL_DRIVER_SOURCE_FILES += $(addprefix $(srcdir)/,$(NWFILTER_DRIVER_SOURCES))
+STATEFUL_DRIVER_SOURCE_FILES += \
+	$(addprefix $(srcdir)/,$(NWFILTER_DRIVER_SOURCES))
+
 EXTRA_DIST += $(NWFILTER_DRIVER_SOURCES)
 
 if WITH_NWFILTER
diff --git a/src/secret/Makefile.inc.am b/src/secret/Makefile.inc.am
index 1ecea1ed4a..959d21099d 100644
--- a/src/secret/Makefile.inc.am
+++ b/src/secret/Makefile.inc.am
@@ -12,7 +12,9 @@ SECRET_UTIL_SOURCES = \
 
 
 DRIVER_SOURCE_FILES += $(addprefix $(srcdir)/,$(SECRET_DRIVER_SOURCES))
-STATEFUL_DRIVER_SOURCE_FILES += $(addprefix $(srcdir)/,$(SECRET_DRIVER_SOURCES))
+STATEFUL_DRIVER_SOURCE_FILES += \
+	$(addprefix $(srcdir)/,$(SECRET_DRIVER_SOURCES))
+
 EXTRA_DIST += \
 	$(SECRET_DRIVER_SOURCES) \
 	$(SECRET_UTIL_SOURCES) \
diff --git a/src/storage/Makefile.inc.am b/src/storage/Makefile.inc.am
index 588df60652..3d453029a7 100644
--- a/src/storage/Makefile.inc.am
+++ b/src/storage/Makefile.inc.am
@@ -89,7 +89,9 @@ STORAGE_HELPER_DISK_SOURCES = \
 	$(NULL)
 
 DRIVER_SOURCE_FILES += $(addprefix $(srcdir)/,$(STORAGE_DRIVER_SOURCES))
-STATEFUL_DRIVER_SOURCE_FILES += $(addprefix $(srcdir)/,$(STORAGE_DRIVER_SOURCES))
+STATEFUL_DRIVER_SOURCE_FILES += \
+	$(addprefix $(srcdir)/,$(STORAGE_DRIVER_SOURCES))
+
 EXTRA_DIST += \
 	$(STORAGE_DRIVER_SOURCES) \
 	$(STORAGE_DRIVER_FS_SOURCES) \