diff --git a/contrib/libarchive/libarchive/test/test_write_format_mtree_preset_digests.c b/contrib/libarchive/libarchive/test/test_write_format_mtree_preset_digests.c
--- a/contrib/libarchive/libarchive/test/test_write_format_mtree_preset_digests.c
+++ b/contrib/libarchive/libarchive/test/test_write_format_mtree_preset_digests.c
@@ -28,6 +28,10 @@
 #define __LIBARCHIVE_BUILD 1
 #include "archive_digest_private.h"
 
+#ifdef memcpy
+#undef memcpy /* FORTIFY_SOURCE */
+#endif
+
 struct expected_digests {
 	unsigned char md5[16];
 	unsigned char rmd160[20];
diff --git a/sys/contrib/openzfs/lib/libspl/include/string.h b/sys/contrib/openzfs/lib/libspl/include/string.h
--- a/sys/contrib/openzfs/lib/libspl/include/string.h
+++ b/sys/contrib/openzfs/lib/libspl/include/string.h
@@ -30,11 +30,11 @@
 
 #include_next <string.h>
 
-#ifndef HAVE_STRLCAT
+#if !defined(HAVE_STRLCAT) && !defined(strlcat)
 extern size_t strlcat(char *dst, const char *src, size_t dstsize);
 #endif
 
-#ifndef HAVE_STRLCPY
+#if !defined(HAVE_STRLCPY) && !defined(strlcpy)
 extern size_t strlcpy(char *dst, const char *src, size_t len);
 #endif