diff --git a/profiles/prefix/darwin/macos/package.mask b/profiles/prefix/darwin/macos/package.mask
index 709360d865d47..8aef87c65608f 100644
--- a/profiles/prefix/darwin/macos/package.mask
+++ b/profiles/prefix/darwin/macos/package.mask
@@ -1,6 +1,11 @@
-# Copyright 1999-2024 Gentoo Authors
+# Copyright 1999-2025 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
+# Sam James <sam@gentoo.org> (2025-04-01)
+# Fails to build w/ `error: implicit declaration of function 'clock_nanosleep'`
+# See bug #951918.
+=sys-libs/gdbm-1.25
+
 # Benda Xu <heroxbd@gentoo.org> (2023-08-20)
 # Does not play well with linkers under macOS.
 # Undefined symbols for architecture x86_64: