diff --git a/src/portab/Makefile.ng b/src/portab/Makefile.ng
index 8712bc5e..30b77fc3 100644
--- a/src/portab/Makefile.ng
+++ b/src/portab/Makefile.ng
@@ -15,7 +15,13 @@ EXTRA_DIST = Makefile.ng
 
 noinst_LIBRARIES = libngportab.a
 
-libngportab_a_SOURCES = strdup.c strndup.c strlcpy.c strtok_r.c vsnprintf.c waitpid.c
+libngportab_a_SOURCES = \
+	strdup.c \
+	strlcpy.c \
+	strndup.c \
+	strtok_r.c \
+	vsnprintf.c \
+	waitpid.c
 
 check_PROGRAMS = portabtest