diff --git a/libctf/ChangeLog b/libctf/ChangeLog
index 6b0a425353..2a37e16cba 100644
--- a/libctf/ChangeLog
+++ b/libctf/ChangeLog
@@ -1,3 +1,8 @@
+2019-06-06  Nick Alcock  <nick.alcock@oracle.com>
+
+	* ctf-archive.c (arc_mmap_header): Mark fd as potentially unused.
+	* ctf-subr.c (ctf_data_protect): Mark both args as potentially unused.
+
 2019-06-05  Nick Alcock  <nick.alcock@oracle.com>
 
 	* ctf-archive.c (ctf_arc_write): Eschew %zi format specifier.
diff --git a/libctf/ctf-archive.c b/libctf/ctf-archive.c
index 24144937a7..5c1692219e 100644
--- a/libctf/ctf-archive.c
+++ b/libctf/ctf-archive.c
@@ -681,7 +681,7 @@ static int arc_mmap_unmap (void *header, size_t headersz, const char **errmsg)
 }
 #else
 /* Map the header in.  Only used on new, empty files.  */
-static void *arc_mmap_header (int fd, size_t headersz)
+static void *arc_mmap_header (int fd _libctf_unused_, size_t headersz)
 {
   void *hdr;
   if ((hdr = malloc (headersz)) == NULL)
diff --git a/libctf/ctf-subr.c b/libctf/ctf-subr.c
index 09ec2951e5..b897351b82 100644
--- a/libctf/ctf-subr.c
+++ b/libctf/ctf-subr.c
@@ -106,7 +106,7 @@ ctf_munmap (void *buf, size_t length _libctf_unused_)
 }
 
 void
-ctf_data_protect (void *buf, size_t size)
+ctf_data_protect (void *buf _libctf_unused_, size_t size _libctf_unused_)
 {
 #ifdef HAVE_MMAP
   /* Must be the same as the check in ctf_data_alloc().  */