diff --git a/Makefile.in b/Makefile.in
index 216ba3d42953266c7a8eff82c2edab15e28520b9..2a940f9082be63e643bfb9f52bab648259525cf7 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -206,6 +206,10 @@ SOURCES = $(nettle_SOURCES) $(hogweed_SOURCES) \
 	  $(getopt_SOURCES) $(internal_SOURCES) \
 	  aesdata.c desdata.c twofishdata.c shadata.c gcmdata.c eccdata.c
 
+# FIXME: $(SOURCES) includes $(OPT_NETTLE_SOURCES) and
+# $(OPT_HOGWEED_SOURCES), which means that inclusion in this list
+# depends on which sources where included in the build. It needs to
+# always include all files, and we no duplicates.
 DISTFILES = $(SOURCES) $(HEADERS) getopt.h getopt_int.h \
 	.bootstrap run-tests \
 	aclocal.m4 configure.ac \